I'm pondering two courses of action for my new-to-me SS Rem 700 7 mag.

Option 1: Leave it 7mm RM, and stretch out the throat to kiss a strategically-seated slippery bullet (Amax or 168 LRAB).

Option 2: With both 7-300 Winmag and 7 Mashburn dies on my shelf, a possible rechamber has its appeal.

I inquired with the good fellow in Chehalis about a rechamber to 7 Rogue, but he expressed concern that his reamer won't clean up a likely-sloppy 7 rem chamber. I'm inclined to believe him, so the question then begs - would your standard-issue 7-300 or 7 Mashburn reamer clean up the factory 7 rem chamber?

If yes, then does anyone know either someone with a reamer for loan or rent, or a smith with the reamer to do the work?

You may have to shorten the throat to kiss, just saying. And I'd shoot it first with a 168 Hybrid as that nose profile might get you close.

I can't speak to oversized factory chambers; but do know at least 2 people off the top of my head,who have punched Rem 700 rifles out to 7mm Mashburn.

One rifle has only been shot a little so far,but exhibits no brass issues and shoots accurately.

The other is owned by a guy who has had the rifle all over the place on BG hunting trips, including to Mexico last year for a record book Desert Sheep. So I guess it's working out pretty well.

He has not complained about any issues that I know of.

Ballistically, they are two peas in a pod.

The Mashburn has a cooler name and history, but there is nothing to recomend one over the other beyond that.

BTW, they are both a terrific upgrade and a good way to boost your rifle.

Vek if the logistics of the wildcat don't make sense for you,the 7RM is fine if you let the throat out for 160-162's. I have done it quite a bit years past and velocities seem to be in the 3100 fps range from 24" barrels. Pretty easy.

Every time one of these Mashburn threads pops up I start thinking. (always dangerous) And my thoughts always go to taking a 7RM case and blowing the shoulder out to the Ackley 40 degree configuration and throating it to take a 162AMax seated long.

I would tend to think this setup would be pretty close to the Mashburn velocity wise.

Also, before the Anti-Ackley faction gets their knickers in a twist, I did not pick the 40 degree idea so I could "overload" to excessive pressures.

I would use it mainly for the case trimming need benefits and a slight increase it powder capacity (i.e. 2%). Also in a pinch one could use 7RM factory ammo with this setup.

If you like tinkering and having something different go mashburn. If you don't like forming brass then I'd let throat out on 7mm remington

Been buying 280AI Nosler brass for some time...have grown lazy about forming brass...

I'd be tempted to let out the throat which won't have to be a lot for the 168 LRAB, and gander at 168g 7mmWB stats (if there are any) for a guideline of sorts

I say you do the 7-300 and sell those old 7mm Mashburn dies...

Alright, so who has a reamer for me to rent/borrow? Conversely, can you point me toward a smith with either reamer?

Thanks,

Sure plenty of smiths anxious to do the deed. Think Kevin Weaver in CO has a 7mm Mashburn, Smokepole used him I think.

If it is new to you, I'd clean hell out of the barrel, and load up either Retumbo or H1000 with 168 Berger Hybrids to see what you have. I quit trying to beat the 7mm Remington and just use it as is.

How soon do you need a reamer? I'm sitting on a new PT&G no throat reamer. But the first cuts will be in my new barrel. Bad news is, my barrel is still 2 or 3 months out. My reamer shipped in about 6 weeks if your looking to get your own.

4D reamer rentals had a reamer when I last checked in with them. I have not seen him here in a long while, but Dober (Mark Dobrenski) has or at least had a 7mm Mashburn Super chamber reamer.

VEK, fwiw, it might save you some hassle. But I'm on my 2nd 7mm Wby in two differ Remington 700's with 24" barrels.

I'm shooting book loads at Mashburn speeds.

Shooting 175's at 3,100 with 5 different powders.

150 LRAB's at 3,300 mv. RL 25

The 7mm Wby with its long neck and freebore make the difference.

I'd second that--the 7Bee is going to be the smartest way to fly--just cleanup chamber, lengthen throat as needed, and still be able to use standard 7RM in pinch. Pressure-tested loads available, headstamped brass, and easy velocity.

I'd be at least the third:)

mine is a 24 inch pipe model and it shoots 150 grain ballistic tips to 3220 with a bit of room to spare, 120 grain x to 3500, 140 grain x to 3330, and 150 swift scirroco to 3180.

personally I was expecting more snap than that but it is pretty consistant and is really more power than I really need.

to be honest I think that the 7mm weatherby might be faster than the mashburn if su35's velocities are correct for EVERY single 7mm weatherby out there.

79 the 150's are bit light but that's about right.Getting the velocity without having things screwed to the floorboards is what it's all about.

The 150 SS II is all copper I think and maybe a bit gummy.

One of our knowledgeable match shooters on here ran his Mashburn to about 3300 with the 150 BT from a Broughton barrel,but ran his ladder and found the accuracy node at about 3250. Recently he worked with the 168 Berger but I can't recall his velocity. He ended up exactly where I did with the 160-162 bullets at 75.5 H1000. I get 3200 with those bullets.



He described the cartridge as a "big easy going slob", not at all fussy and temperamental like some 7 mags can be.

We have not run anything lighter than 160 in any of ours back here.

i had a rem. 7mm mag. barrel opened up to the mashburn, no problems shoots fine.

Ed

The swift scirroco is a fused lead core bullet that is about as long as the 160 grain accubond.

79 yes I thought so....I have shot the old and new versions.

Yup, pretty sure that it is--especially when pressures run in similar levels.

DD: Have you loaded for either one?

Are you talking about me Bob?




I ended doing alittle tweeking and running the 75.5g load of H1000 with the 168g Berger. Say 3120/3140 fps.
Single digit Standard Deviation.An 8, last I checked.
The tweeking was a seating depth change from about .005 off to about .030 off.
The last two 3 shot groups measued 2.5 and 1.015 at 400 yards.
I have never seen any Weathbery in any configuration shoot with this rifle for accuracy.
Period.

dave

79 you may find this interesting.

" The big cases like the Mashburn show more gain over the smaller cases like the S&H, Weatherby,and Remington with heavy bullets than with light bullets..." "Guns, Loads and Hunting Tips"; Bob Hagel.

This will show up if you load extensively for progressively larger cases in the same caliber and I have seen this with the 300 WM vs the 300 Weatherby; the 338 vs the 340; the 375 H&H vs the 375 AI;the 7x57 vs the 280,and on it goes. Gunscribes who have seen the same thing and written about it include not only Hagel, but Bob Chatfield -Taylor as well....which goes to show, it isn't recent "news".

And...." After developing loads to maximum trouble free hunting pressures for 7mm cartridges ranging in capacity from the little 7/08...to the big 7mm-300 Weatherby wildcat, it seems the Mashburn Super Magnum has about the optimum powder capacity for the .284-inch bore diameter with available powders......The Mashburn offers only about 100 fps over the 7mm Remington and 7mm Weatherby cases,but whatever advantage there is lies with the slightly larger case." Guns, Loads, and Hunting Tips; Bob Hagel.

Yes Dave I was talking about you.

Hi Bob.
I was thinking that my version of H1000 could be the "slow" one.
I could care less with the way it shoots.
I did not go nutzoid BR to get this kind of accuracy either.
Just looking at it I had a "feel" that it needed alittle more jump and it responded in kind.
I will eventually do a write up on my Mashburn experience.
Just dont tell anyone I was shooting 1 inch groups at 400 yards with a 10x FFP zeiss...

dave

Nope, not at all, but I can read. I think that the other thread where that was discussed pretty well showed the data for the 7Bee can be trusted to at least equal, if not outperform, the Mashburn at equal pressures.

Another way of me saying: I'm a believer in the pressure/velocity advantages of significant freebore. I suppose one could freebore the Mashburn and go for broke.

As an aside, and a bit different topic, but I'd never want a wildcat for my main big game rifle when a factory option was readily available with the same performance, and one with the flexibility to use one of the most popular rounds in existence in a pinch (7RM in a 7Bee). I'm not "adventurous" that way, as I see it as but one more possible thing to go wrong somehow.

I am thinking I might try shooting a 7mm RemMag and 7mm WBY through my Mashburn Super. I have done this with a 300WinMag and 300 H&H in a 300WBY and because they all headspace on the front of the belt, the shorter 7's should run in the Mashburn chamber just fine. The belted 30's all did great, and the 300Win in the WBY chamber even gave really good accuracy and very little loss in velocity. Not really a measureable amount.

This experiment, if I get around to it, will make for an interesting argument that the Mashburn round is the more versatile and more goof proof if ammo is lost or otherwise not on hand.

I did not think you had.

So you concluded that the pressures for the Mashburn are equal to the Weatherby,without having loaded for either one? Based on what you read,and without loading for either?

How do you know that the Mashburn pressures are not lower?

Fact is you don't...and neither do I;and neither does anyone posting here who has not measured them.

I do agree with you on the freebore. It's the reason (along with a pressure ceiling of 65,000 psi) that the Weatherby even comes close to the Mashburn. That's a characteristic of the rifle,and not a valid comparison of the cartridges.

Might be interesting to see what the Weatherby does with no freebore. I think Page/Hagel/Mashburn all knew since they among them had done the testing......which is why they all flew right past it when it was sitting there all along.

BTW, with lighter bullets there still is an advantage for the Mashburn VS the Remington. With 120gr TTSX's I am getting 3700fps. Mule Deer bucks, near or far, really hate this load.....

safari man did you blow anything up with that load?

Starting the Rifling part way down a barrel always drops your pressure Bob.
Every rifle i've shot the throat out of tells me the same thing.

dave

Gents, it appears to me that a 7-300WM, the Mashburn, & the 7mm WB are all identical if loaded to the same pressuure and throated the same for a particular bullet to increase the case capacity without employing freebore.

What am I missing? The differences in the reported fps results aren't the cartridges as case capacities are practically identical.

My question's are:

1). Which brass is easier to form... the Mashburn or 7-300 WM?

2). How many chamber/reamer variations are there for the Mashburn vs the 7-300 WM?

Not at all. In my rifle, with its 26 inch bbl and Ulta Bore Coat plus Moly Coated bullets seated away from the lands a bit, that load is just fine.

Dave true. Assuming you could ever get the barrels the same(good luck with that!) then case capacity becomes the factor. The Mashburn is a larger case.

Tom I believe the Weatherby has less capacity than the Mashburn and 7mm/300 Win Mag.

Brad far as I know there is not much more variation with Mashburn reamers than what we might see from custom reamers for anything else..of course there will always be some depending on who made them.

The 7mm/300 win mag, I can't say because I never owned one.

I think there would not be enough difference between the 7mm/300WM and the Mashburn to spit on. About all you have with the 7mm/300 WM is a shorter neck. This makes sense since the Mashburn and the 300 WM are the only two belted magnums I know of with that case length.

In fact one thing I have noticed once data started flowing in from various folks and quite a few rifles recently built, is how close everyone was in terms of velocities and powder charges, too, for that matter. No more variation than I was used to seeing from other cartridges.

Brad I'm sure there are minor variations in reamers, but no more than we'll see in any custom reamers. For a wildcat, it's pretty well established, having been around for 5 decades or so. RCBS has carried dies and form /trim dies as a pretty much standard item.

When I ordered dies from Redding, they did not make them. My understanding is that the first Redding dies for the Mashburn Super were cut based on dimensions taken from cases fired in my rifle, which was chambered with Dober's reamer. So there may be some variation but no one seems to be complaining about any issues that I know of.





If anyone wants to know more it's easy to go read what Hagel said about it. I will get the issue of Rifle magazine in which he did his article on the cartridge and post it on here. To confirm further, they can grab a reamer,chamber a rifle, and find out for themselves what it's all about.

Agreed on all points, which is why I would trust the tested pressures of a 7Bee over any wildcat claims. Physics trump experience, in my experience! I have assumed that the reason they didn't go Bee when developing the Mashburn is because they did not like freebore due to its possible accuracy limitations (or that they simply wanted their own names on something).

Gotta love this Christmas gack though! I doubt I'll ever chamber for any of them anyway.

It looks to me that the factory WB case would have slightly less...but if the 7WB is throated for 160s (non VLDs) as the Mashburn, then we have the very same breed of cat.

Am plotting to have my 7mmWB throated to the 168g LRAB, if I can snag some. It has no freebore with 140/150s currently.

Guys you can read all about it in Rifle #103,January/February 1986 issue. That's where Hagels article is.

There are even some nice pictures for those who have doubts about the size of the Mashburn case vs the Remington and Weatherby cases. Hagel did a good job laying it all out without a lot of needless speculation by those who never had one, which is always a bit distracting.

Enjoy. Merry Christmas!

Past century, past millennium, before half the people here were even born. Golly--get with the times Bob! Next you'll be recommending that a Mashburn be built on a Winny pre64.

Dakota, I have the article mentioned by Bob, and I read it as a middle aged adult the first time!!!! Your mention of a past century and past millennium sure make me feel very OLD!!

All in jest! Wisdom only comes through experience, and experience mostly accumulates over time.

And that is how it was taken, but it still makes me feel my age!!!!

I believe I read that in 1986 and still have the rag...

FWIW - I have the same Rem 700 Classic in 7 Wby Mag with a 24" barrel as SU35 does. I'm sure that I can't reach any of the speeds that SU35 posted in his threads without excessive pressures.

My rifle has the normal Bee freebore, but I could only get 3000 - 3030 fps with the 168 LRAB using 7827ssc, Retumbo, H1000 and Rel 25 before pressures got dicey. And that bullet shoots for crap in my rifle too. I have not found any 175 LRAB's to shoot but I have no doubt that I could not reach 3100 fps safely with that bullet.

The 160 Partition with a COAL of 3.550" would go up to 3200 fps but I felt that I was standing on it to get there. As a reality check, I ran some Weatherby factory 160 Partition's thru it and they clocked 3058 fps with an ES of 5 and with much better accuracy. So I dropped the charge back 2 grains and settled on my hunting load using Retumbo under a 160 Partition moving out at 3085 fps. Maybe it can take more pressure, maybe not but it will kill just fine at that speed.

Data from my rifle with SAAMI standard COAL;
Factory Weatherby 175 Hornady ammo clocks 2930 fps with an ES of 7. Groups are less than 1 moa.
Factory Weatherby 160 Nosler Partition ammo clocks 3058 fps with an ES of 7. Groups are less than 1 moa.
Factory Weatherby 140 Nosler Partition ammo only shows 3160 fps with a much higher ES of 25. Groups are a little larger than 1 moa.

My opinion is that the 7 Wby is a little more than a 7 Remmy and a little less than the Mashburn - kind of right in the middle.

Thanks Bob.

Back to my first question, which brass is easier to form?

Thinking about it, likely the 7-300WM would be as it needs no fire-forming, yes? Just necking down a 300WM?

If that is indeed the case I'd go with the 7-300WM.

You can make Mashburn brass with just the loading die. Insert .300 WM brass and the die will both size the neck down and push the shoulder back at the same time. A lot of folks haven't bought form/trim dies for the Mashburn.

I get 3250 from 76 gr. of RL-25 and a 162 Hornady Interlock, 24 in. Shilen SS barrel, with unlimited brass life. My only problem is with having to anneal the brass. Primer pockets haven't gotten loose after 10 reloadings or so. YMMV

I would say to be very careful short throating a Wby .
Fine if you always run hand loads.
But try running Wby factory ammo in a short throat and you can run into trouble real quick.
Saw it with a 257 Wby my smith had.
The guy had short throated the thing and ran out of his hand loads and picked up a box of factory ammo. Guy was dammed luckey he didnt eat it.
As for case forming.
I just stroked 300 WM cases with some imperial sizing die wax on them and out poped cases ready to FF.
In my mind 25 rounds on steel off hand is never a waist of time.
I had a 7mm Wby many years ago.
I would never own another.
dave

Never been a fan of that short neck on the 300 case.
Making a 7mm out of it wouldn't help.
The thing I see with the Mashburn is a longish neck and a 30 degree shoulder.
Looks an awful like the stuff I run at 1000 yards.
I havent shot the Mashburn at 1000.
But from what im seeing.
I wouldn't be afraid to try it.

dave

Roger that, no factory ammo was ever planned to go down this tube. It is throated as I said for 140s & 150LRABs. Do prefer the longer neck over its counterpart...fwiw, this case is the entire extent of my interest in all things WB.

And as you might expect it provides book fps a few grains below book guidance.

Played with freebore in an M-70 280Hawk out of curiosity some time ago--if there is an advantage to it I never could find it. The differences among individual chambers/barrels and their relationships to loads, appear adequate to me to support all sorts of marketing claims and handloading consensus.

The internet has magnified that with one posters findings being eternally repeated by non-users. A good example being "you can't handhold 15x binoculars" becoming a bino mantra.

This particular rifle is the most accurate 7mm I ever owned. Touch heavy but very gratifying...

My factory WBY 7mm was a mark 5.
Its been awhile but it soured me on mags for many years.
Its a apples and oranges type of thing.
A factory Wby against a full on custom is not really fair to Wby.
But I still wont repeat..
To me the Mashburn beats all commers in the large case 7mm race.

I carried a 280 AI for almost 20 years all over NA and Canada.
It did everything I wanted. But then all I ever hunted was deer...

Im have tempted to hubble up on my Mashburn and go kill some steel at 1000.
Its a rare thing to have a sub 9 pound rifle shoot like mine does and I know it.

The Mashburn impresses me.
I really like the long neck and shoulder angle.
Once the cases are ironed out its just a big non fussy pussy cat.
Not hard to see at all why Dober and Bob like it so much.
Of all the rifles I have right now.And I have a few.
If I was headed out on an important hunt.
The Mashburn would get the nod.


dave

Fair may be comparing actual loaded case capacity with same measured pressures. It would be a short thread. Fortunately for the sake of continuing endless campfire discussions about the same topic, most handloaders don't have labs.

In the end the rifle and it's performance is what makes it a favorite...for me. Favorite cartridges don't always translate into favorite rifles...though my intentions were good.

Until someone can prove to me that the 7mmWB case (unfairly)..throated like a Mashburn is any more that the same thing dressed differently, will stick with current opinion that a grain or two either direction in case capacity makes no difference-that realm is within the lordship of the barrel (loaded to the same pressure).

Someone could do that easily enough if that someone provided the water capacity of both cases...edit--actually just the water weight of a formed mashburn case filled to the to top would do it for me...:)

Well, I ordered a set of 7mm Mashburn Super Magnum dies.. Pretty sure I have a lead on a reamer and some GO/NO Go gauges as well.. I have an old 7mm Rem Mag begging to get rechambered. Looking forward to working with it.

I read alot about pressure on this board.
Very few people have the means to actually measure pressure.
Fewer still have the knowledge interpret it in any meaningful way.
Like you say it would be a very short thread.
I look at the Mashburn and I see Safariman lighting off 120 TTSXs at 3700fps and hes still with us..
I see Dober running 150 NBTs killing elk and anything else he runs across for many years with no problems.
I see myself heading down the Berger path.Im just about the last guy on Earth that would agree with Mr.John Burns about anything and yet I managed to drill my freezer doe at 200 yards a couple weeks ago and it thats where it is right now..in the freezer.It worked and the accuracy im seeing is close to what im getting with my full on BR 1000 yard stuff..Its nuts.
And I see Bob and company.
Lobbing uber NPTs and TBBCs at stupid distances with uber reliability.
No peekie pressure oddball reports from anyone.
Just solid performance.
Just solid accuracy.
And if you have a mind to you can go back and dig up all the stuff all the 50s and 60s gun writers had to say about it back in the day.
For a few grains of powder either way.
Ill stick with the Mashburn .

dave

Tom if that "someone" you're referring to, is me, I would gently suggest that those interested can go do it themselves. I didn't build mine,shoot it,and report on it to enter into any silly contest to prove it's the fastest 7mm magnum out there. If that were the goal I'd have bought a 7 RUM and been done with it.

I report what I see,and if that's not enough then everyone is free to go do there own thing and figure it out for themselves. I sure don't get paid for this and being an info lackey for a bunch of naysayers who have no experience with something but want me to "prove" to them, isn't on my radar.

The notion of free entitlement to information on this place is unreal.

You want to challenge,learn for yourself, you go do the work yourself. Sure don't owe you nor anyone else on here,any explanations nor information.

Merry Christmas gents!

I certainly was not. If I have anything to say to you, I will address it to you.

I was simply asking Dave for a case capacity measurement. Since when is asking for info an entitlement on this board?

Chill out. What is there in my posts to get defensive about and say that chit to me?

I think your going to like it.
The 168g Berger classic hunting bullet fit in my M700 at zero on the lands with no problems.
Right now its very hard to find win brass so I ran Norma.
I like the Norma brass alot.
I see negative stuff written about Norma brass being soft.But have yet to see it myself.
If I were you i'd go to a 160g plus bullet of some kind and pick up a pant load of H1000.
Some where along the line you will have a smile on your face..

dave

Thank you Dave. Appreciate the information.

I have been running Norma brass in a few other cartridges with no issues at all, so I suspect the 300 Win stuff will be similar.

I would imagine it'll get fed a steady diet of 160 AB's or 175 PT's as I'd like it to be my light'er weight elk rifle..

I actually have both the wby and mash and could do it for you.
Problem is im not at home right now.
The sad experience with wby accuracy I had would never allow me to recommend it to anyone.
And I dont care how its freebored.
I dont even care for the way wby the case looks.
Double radius BS is just that.BS.
Been there done that wont be repeating...ever.

To me the Mashburn is a Superior case design over the wby plus or minus a couple of grains notwithstanding...

dave

Really going over the top a bit are you? Maybe you have a 7mm WBY that doesn't shoot but I have one and it is old as hell in a Fibermark stock and it is SUBMOA with any factory Weatherby Ammo i put in it and the 150's BT come out at just under 3300 fps . It also can be quickly identified as a 7mm Weatherby by its case stamp isn't that novel? I don't have to buy a reamer,sizing die and extra cost reloading dies unless I were to build a custom 7mm wby on a 700 action.

Is some animal going to not die because of a 50fps difference in velocity?

I just can�t think of a practical reason to build a Mashburn over a 7 Weatherby.

�Because I want to� is a suitable reason for putting together a wildcat chambering when a factory cartridge that does the same thing is available, but it really doesn�t make sense from a pragmatic standpoint, due to the added cost of custom dies and what not.

I understand the "coolness and uniqueness " of a Mashburn. I just don't understand the weatherby bashing . BTW I never got anywhere near the speeds with multiple 7 Rem mags that I get with this Weatherby.

Will PM you

I dont think so.
This is after all, the Custom rifles and Wildcats board.
Why do bother to even come here?
I have not shot a factory loaded round of ammo in over 30 years.
Not about to start now
That the Wby has a BS double radius shoulder and has the name stamped on the case is about a meaning less a thing as I can think of.
The Fibermark I had would shoot 1.5 inch groups all day long and on Sunday.And in a case of this nature.A company only has one chance with me to make a good first impression.
They failed.
Epic fail.
If shooting factory ammo with a rifle where the rifliing starts part way down the barrel trips your trigger and the stock concentrates every oz. of recoil right down onto you is your thing than im happy for you.
Glad its working for ya.
I will continue to pass and have done pretty well doing so.

dave

Because I love to see that a cartridge that requires 12 trick moves to create does no better then a Factory cartridge that has been around for 60 years. Sounds like a canned response on your end and that is an epic fail. Why should I hand load when the rifle Ihave shoots sub moa every day and sunday?

Then why post on a Wildcat board.?
Sounds like a simple neck sizing shoulder bump is a bit of a technical challenge for you.
But thats ok.
If you ever need any help reloading.
Im here for you.
I have shot and reloaded for both the 7mm Wby and the 7mm Mashburn.
Im actually one of the few.
The 7mm Wby was developed by a insurance salesmen.
The 7mm Mashburn is a rifleman's cartridge developed by a true rifleman.
Since you dont handload I can understand your reluctance to accept that the Mashburn is superior to the wby in every way.
But thats ok.
I have 35 years reloading experience and im a 1000 yard bench rest shooter.
Im here for you.

dave

Done posting on this topic with those with closed minds. Sayonara

I've only worked with two wildcats in 40 + years of hand loading.


We really shouldn't turn this into a "Why wildcat?" thread but while we are at it...we might as well.

Best answer is that it's a logical extension of hand loading ammo.

Ever have a rifle that shot best with once fired brass? If so, you "wildcatted" a factory cartridge,by fitting a factory cartridge to your rifle to optimize its performance. It's unique to your rifle.

Cost of dies? Most wildcat dies cost no more than a set of Redding Comp dies,another little "trick move" to optimize your rifle's performance. As hand loaders we do it all the time. Besides, the wildcatter is paying for it out of pocket. I never let the cost of a set of dies keep me from a cartridge I really wanted,factory or otherwise.

Time forming cases? I'm stuffing hulls and shooting anyway...what difference does it make if I am forming brass or firing factory stuff or loading my formed wildcat cartridges? It's all the same thing.

The "hardest" part is forming some brass,which ain't hard. I could teach a [bleep] to form a Mashburn case. None of this is "hard",nor time consuming if you are a hard core shooter and hand loader anyway. .of course you may be the type who wants the factories to do all the voodoo/black magic stuff for you.

Another reason is that after awhile ,and exposure to nothing but factory cartridges, you are just stuffing hulls...the process gets boring if you have already worked with a lot of cartridges. Wildcatting puts a little zip back in the game.

There's also the intangible satisfaction part...ever catch a trout on a fly you tied? A Bass on a jig you poured? Ever build a raft as a kid, push it out on an unnamed pond and catch fish? Build your own bow and arrows from hardwood switches and kill squirrels with it?

.......or did you depend on some factory to do all this stuff for you?

If it weren't for wildcatters you would not have:

The entire lineup of Weatherby cartridges.

The RUM lineup.
280AI
7 Rem mag
243 Winchester
25/06
22-250
257 Roberts
260 Remington
7/08 Remington
338/06
6.5/284
6mm Remington
6.5 Creedmoor
6XC
7STW

I could go on, but the point is, none of these saw the first light of day from any factory...all were initially developed by wildcatters and later adopted by factories. So the factory load shooters can have something to play with and tell the wildcatters what wild-eyed loonies they are....

Bob, I understand the draw of the wildcat. I've made my one of my own, the 6mm Stuver (6mm-6.5x55 blown out with minimal body taper and a 40 degree shoulder). But I won't for a minute tell anyone that it makes sense, or that anyone should chamber it over a readily available round, or even a semi-common wildcat such as the 6mm Ackley. Because it doesn't do anything special.

A bunch of those rounds you mentioned actually filled some sort of niche, however small, and were not directly copying a round already available from the factory. If they were, it was because they offered some other sort of benefit, such as the ability to fit VLD type bullets nicely in a short action (6.5 Creedmoor).

I'm just not real sure what the 7mm Mashburn does better than the 7 Weatherby. I've read Hagel's stuff, and read on here for years about the Mashburn. It's seems to me that the reason the Mashburn is still being chambered is that it's proponents want a wildcat for the sake of owning a wildcat, and will look for any small advantage (real or imagined) and run with it. Taking something that's relatively simple and making it complicated. So is the wildcatter/rifle looney way!

I have nothing against the Mashburn. I have nothing against wildcats. I just think we should all be realistic with ourselves and realize that the vast majority of the differences we are seeing between these rounds exists solely between our ears.

Then why post on a Wildcat board.?
Sounds like a simple neck sizing shoulder bump is a bit of a technical challenge for you.

Yep sounds like too much work and the case stamp doesn't match ask me why
Never have found that to be a problem and I think we are back to the technical challenge part for you.I did offer my help.
But thats ok.
If you ever need any help reloading.
see comment below
I have,didnt think much of it.
Im here for you.
I have shot and reloaded for both the 7mm Wby and the 7mm Mashburn.
Do you need special recognition for that:
No not at all.When I go into a chat room on a subject I know very little about ,like you in this instance.I generally keep my pie hole shut and try to learn something.Unlike you.
Im actually one of the few.
WOW aren't you special
Well thank you very much.All complements accepted.
The 7mm Wby was developed by a insurance salesmen.
So what do you do for a living?
Im a quality auditor for one of the largest corporations in the world.
The 7mm Mashburn is a rifleman's cartridge developed by a true rifleman.
BFD
Actually it is a BFD.If you had even a basic understanding of case design you would be able to understand that.But you dont.
Since you dont handload I can understand your reluctance to accept that the Mashburn is superior to the wby in every way.
DOn't need to hand load my 7mm WBY other rounds i do because they get shot more
This is a wildcat chat board.We handload here.
But thats ok.
I have 35 years reloading experience and im a 1000 yard bench rest shooter.
Thats fantastic
Well thank you very much.All complements accepted.
Im here for you.
You come across as a total pompous ass. There is zero chance we would ever be civil with each other.
Too bad thats your loss.And even now if you asked for advise or help.Im here for you.

Done posting on this topic with those with closed minds. Sayonara

Sayonara dude.
Dont go away mad.
Just go away.
If the panties are a bit to tight just re-ajust and consider it a learning experience

dave

its like groundhog day.

U R welcome.
Sounds like a plan.
Im thinking a harder bullet would be a good thing on an elk.
The Bergers seem to work fine on deer sized game.
dave

SS M70?

pg you are right...there is a huge amount of overlap ballistically with or without the wildcat. I for one could never understand the 280AI niche.

But when I built the Mashburn I wasn't trying to fill any gap;I was itching to build something and had already been through 7 Rem Mags numbering in the teens,the 7mm Dakota,the 7mm STW, several 280's etc etc.

The Weatherby was not going to do it...I don't like the rifles, the freebore,nor the Norma brass.I had just come off bad brass experiences with Dakota stuff made by Norma,which also made me want to stay away from things like the LRM and other makers of boutique cartridges and brass)

Besides, I have built a couple of 7 Rem Mags based on long throats on H&H magazines that, literally, used 7mm Weatherby data for a slight uptick in velocities.So there was no appeal there, and still isn't.

The Mashburn was the only 7mm magnum that appealed to me at all. I have all the parts sitting over here in the form of a M70 Classic 7 RM,Borden RR ,and Brux tube.....I am on the cusp of doing a second one.


But fill a gap? Nope There are no gaps anymore

Besides I have always been a Page/Hagel fan. I was curious if the old wildcat performed up to what they said,wanted to find out for myself rather than speculate, That's my nature. It does.

Quality Auditor ...LOL that explains it all.

Yes it does, we have to get it right.
Every time.
I thought you were done posting on this topic?
Guess not.

dave

Bob,

Why no like for the "freebore?" What's the negatives?

One of the main components of achieving VERY accurate rifles is to get the bullet started straight in the barrel. A lot depends on the chamber, and if the chamber enters the bore perfectly straight. Excessive Freebore allows and encourages the bullet to get started crooked in the bore. How much excessive freebore degrades accuracy is a matter of trial and error.

Hint: for the guys that want freebore in their custom rifles, design the reamer with 0.0003-0.0005 over bullet dia. throat, which will go a long ways in keeping the bullet aligned with the bore.

DD: Basically what Keith said.

IME, I have dicked around with enough barrels and various throats with longish throats to know some will shoot with substantial jump to the lands (if tolerances are kept tight),and some are on the sloppy side and won't. I have had factory rifles that I had to lengthen mag boxes for longer OAL so I could get closer,and then they shot.

Just as an example, I have never shot a 340 Weatherby that was not accurate and grouped well. But not all 300 Weatherby's did. 340's are not free bored,at least those I helped load for were not. OTOH, 300's are.

In any event it was not a condition I wanted to take a chance on in a custom rifle costing a few thousand dollars.

When designing a Weatherby reamer with short freebore, cut the neck length short enough to where factory ammo will not chamber, did this on a 257 Weatherby so that I could reform 264 WM and 7 Mag cases.

Again, .0003-.0005 throat dia on freebore will work to keep the bullet straight. A throat that is .003 over bullet dia is a disaster to accuracy....take that to the bank.

My 7/300 is easy, I just run a 300 WM thru a 7 mag die to resize the neck and after the first firing resize with a Redding bushing die in 300 win mag die with the bushing changed out to. 7 mm. The first round is just as accurate as the second because when I resize to 7 mm I leave a little crush fit in the neck for a slightly tighter fit

I run 140s to 3300 with no problem with 7828 and Winchester Brass

Steve I used to form your case the same way wile playing around at the loading bench but never chambered for it.

RinB on here had a pal who did,and we used to talk a lot about it.Obviously they are the same/same with the Mashburn but a shorter neck.

Bob,
Same same.The 7mm Practical.
http://www.ballisticstudies.com/Knowledgebase/7mm+Practical.html
The fact that you can buy 7mm Mashburn S bushing dies off the shelf at Redding...although it took awhile to get them.....makes it pretty easy.

dave

Dave yes; I had read about the Practical.Like i said I was forming that case while goofing around the loading bench years back.

There isn't much to choose between it and the Mashburn. The author distinguishing between the two on the basis that the Mashburn was originally formed from 300H&H brass is somewhat true, but has not been so since Bob Hagel started using 300 WIN Mag brass to form Mashburn brass 30+ years ago.

In terms of performance, they are the same.Both cases hold more powder than a 7 Rem Mag.The Mashburn neck is longer if that's important to some people.

When we ordered Mashburn dies from Redding they did not make any...my FL dies were made from scratch with brass fired in my rifle. I did not know they made the S Bushing dies now. They must have added them to the line.

If I can make a suggestion, if you order Mashburn dies from Redding have a candid conversation with them and be VERY specific about neck diameter.

I bought a set from them a couple years back. They gave me the choice of a standard FL sizer or the first Bushing die off the line. I thought I was saving a few bucks and went with the standard FL sizer. Bad decision.

The problem? The sizer die sans expander ball produced an outside neck diameter of 0.292". Absolutely stupid. That's a whole 2 whole thou larger than my 6.5X55 die, and I run a .290 bushing in my 260 Rem competition Redding sizer die. After the case is run into the neck of the sizer die, the expander ball has to neck it back up 20 thou. Yup, you read that right.

Redding were lazy or didn't think through specifications. Nothing like having to reef upwards on the press handle to get the expander ball back through the case neck.

I called Redding about it and they didn't care. Suggested I send the sizer die out to be reamed so it was usable. Yeah, nice...pay $175 for custom dies and need to have them fixed by a third party.

My gunsmith had to anneal the die to soften it, run in a .308 throater, then reharden it. Using WW 300 Win brass, that takes the neck down about 6 thou and necks it back up 4 on the expander ball. That's plenty to ensure you can use about any brand of brass, and works the brass neck no more than necessary. Makes straighter ammo as well.

If I was to have Redding make "custom" Mashburn dies again, I would be specifying a .308" neck diameter sans expander ball. If they wouldn't, I would go bushing dies or go somewhere else.

A simple solution to that problem would be to totally ditch the expander ball.Have the neck of the die counterbored out to accept a Wilson/Redding bushing.This way you could size the neck to whatever you wanted.Then buy a cheep hand decapper.
Problem solved.
My smith had a 7mm Mashburn die from RCBS.
I had to borrow it for awhile and it worked fine.
I loose the expander ball in every round I get serious about everytime.
I get much less runout that way.

dave

Agreed, and I normally do so as well. But if the diameter is correct and you use an expander ball to bump back up a thou or two it doesn't result in less straight ammo. If you are talking your typical die which necks down a bunch more than necessary of course you are correct.

To have the die bored out you still need to have it annealed. The die from the factory is way too hard to be able to counterbore or ream.

Much simpler to go bushing or have the diameter specified from the get go. With that die, if you just ditched the expander ball you could also just use 6.5 bullets!

Do you mind sharing how much 7828 to get there? Does it seem to you like there is room for more powder and speed with that load?

Rick I did not know about any of this....will check mine but can't recall a problem.....mmmmm

One of the problems with a 7mm Rem Mag AI, not that it is a problem, is that you still have a very short neck length.
One of the very things that 300 Win mags and 7mm Rem mags are noted for.
Longish necks and 30 degree shoulders rule.
Especially when lobbing heavy per caliber bullets..
And Parker O. Ackley is my hero by the way..
A 300 Win mag case stroked in a 7mm Mashburn Die is closer to final net shape than blowing a 7mm RM AI.
Ammo.
I see the....if I loose ammo thing about wildcats alot....
If you loose your ammo.
Your pretty much screwed no matter what kind of gun you have.
Putting some different kind of ammo in your rifle on an important hunt would be just like usuing someone elses rifle.
Might was well just start over....


dave

Dave7mm,

I am going to test this in my own 7mm/300 WinMag soon, but just like I have fired 300Win and 300 H&H in a 300WBY, I can see absolutely no reason why, with headspacing being done at the forward edge of the belt, that one could not safely fire a plain vanilla 7mm RemMAg, 7mm WBY, 7x61 Sharpe and Harte or a 7mm Mashburn Super in a 7mm/300 WinMag chamber. The only downside to doing so would be pretty low and maybe non magnum velocities since one would be firing what amounts to a pretty mild powder charge in the larger case. Chamber/FINAL case dimension is what determines peak pressure and thus velocity.

Nope, it is my old, Model 70 XTR 7mm Rem Mag. Been sitting in the safe collecting dust for a few years since I got the 7mm WSM. Figure I might as well do something good with it. Forming 7 MSM cases from 300 Win Mag is a cinch compared to 375 to 35 Newton..

Here are a couple of reformed cases for the 7mm MSM.. I had some old R-P 300 Win Mag cases laying around from my old 300 Win Mag. I merely ran them up into the FL 7mm MSM dies and voila...

Here is the 7mm MSM next to the 7mm Rem Mag.



I couldn't help myself and loaded up a few more dummies..



The 160 AB is seated right at 3.600 COAL.. The 162 AMAX went a little longer at the same die setting.

Also, the case isn't fireformed yet. It won't be drastic, but the little bit of taper in the 300 Win case will get blown out during fireforming, so it'll pick up a little more space there as well.

I also swapped over the mag box in my old Model 70 7mm Rem Mag. Well, technically I knocked out the spacer to make room for a 300 H&H follower. Works very slick now. I also fitted a 300 Wby bolt stop to allow my bolt to come back full stroke.. Really easy stuff.



Nothing special about the rifle, just an old M70 XTR Sporter. I through it in a B&C Medalist and cerracoated it as well.

Well, here are some results from the fireform loads.. Overall, I could just about hunt happily with the fireform loads the way they sit now. A little seating on the 140 AB and it would be good to go!

Here is the 139 grain Hornady, Hornady Case, 3.520" COAL and CCI250 primer.



Speeds ran pretty much around 3200 from what I could tell.



The 140 AB's were a COAL of 3.575". Everything else was the same..



They ran about 25FPS faster than the Hornady's..



What I was surprised about the was the POI difference. Both groups were shot using the center bull. The 139 SPBT was zeroed about 2" high, while the AB's went high and to the right. Not a big deal, but it was drastic for two bullets that differ about 1 grain!



At 3200 with a 140, this thing is just loafing along, even with IMR4350 which is a big on the fast side, but everything worked well. Cases chambered tightly with a good crush fit, but they extracted with no resistance at all..

The rifle shoots well and it's pretty gentle. I just put an old M8 4X on it for now. Not sure what I will put on it for hunting, maybe nothing different.. Who knows..



Either way, for a 120 bucks for the rechamber, I am calling it a success so far. Doesn't seem to be overly fussy. Once I get a few more empty cases, I'll load them up with some 160 AB's and see what happens..

" Doesn't seem to be overly fussy "

Is the term that everyone I know that has one says after they play with it.
Even for alittle bit...


dave

Seems like it. Can't wait to get it out tomorrow. Got some 160's loaded with H1000. Should be a nice morning.

Can you kiss lands with the 162 and fit in the magazine?

Yes. You can with mine. It's a wildcat and reamers vary.

I couldn't tell you to be honest. Haven't tried it.

I'll give it a whirl the next time I load some more up.

Okay, so I knew from last time out I wanted to shorten my rounds up about .010" since I was getting the 2 in and 1 out. I also split my load with 75, 75.5 and 76 and here is what I ended up with..



Averaged out to 3210 today over the chrono. So, I am happy. I am sure I could monkey with it, but honestly I am very happy with it. I met my goals with it. 3200 with a 160.

I know there is more speed to be had, if I dropped down to a Retumbo or RL33, but I am good with the consistency I am getting with H1000.

Also, I have a sweet shooting deer load with the 140 AB and IMR4350 at 3200. I figure the 280 Ackley guys are on to something there. The nice thing is it is really easy shooting load in the MSM.



I figure I can monkey with it as time permits, now that I have the main load out of the way.

So, all in all, not counting the fireforming loads, it took 12 rounds to find my powder charge, then 9 rounds today to find the seating depth.. Pretty happy with it.

Cartridge was very mild mannered across the board. Case forming is nothing more than I do with new brass anyhow, so turning 300 Win Mag cases into Mashburn cases was too easy.



Speed came pretty easily without feeling like I was standing on it. The cases all have three firings on them and they seem tight. Even the couple I ran up to 77 grains that were hot stayed tight, so the Hornady brass is holding up well.

My box is 3.630" and I just tried a 162 AMax and saw rifling marks on the bullet when I chambered it at 3.630", so I'd say YUP..

Well, I took the Mashburn out yesterday, just wanted to run a few rounds through it to see how well the 160 AB, 75.5 grains of H1000, CCI 250 and reformed HDY cases are holding up...

Pretty happy with it..





Feel like I am ready to stretch it out a little...

Nice Scotty. That works.

Of course we knew it would. Not too hard huh?

That's your factory barrel re chambered, right?

Is there much difference between the Mashburn and the 284 Jarret round.

The 7mm RM is just fine.

Instead a more effective upgrade would be to trade in that entry level 700 for a better designed rifle.

If only your mother followed the same advice.....

Bertzs,

Looks to me like you have found some great loads for your rifle! Congratulations on a terrific upgrade and the results you are getting. I hope as much for mine when I am feeling up to toying with it again.

I am going to see how fast I can run some Moly'ed 140's of various manufactureres and hopefully report back here.

The last two years I ran Moly'ed Barnes 120gr TTSX's at 3600fps and they were terrific. Just going to toy with some bullets with a bit more BC. My rifle will be a deer rifle only, so no need to play with heavies here. And, I would have no fear of punching an Elk with a TTSX 120 or 140 if I needed to.

Thanks for the report, data and pictures here. I am so drinking in all of the 7mm MSM talk. Makes me miss Dober just a little bit less, him having been the resident (and very succesfull) 7Mashy pusher here for a long time.

154 Hornady at 3290 fps. 7mm Bee Euromark

Beretz rifle is a M70 PF punched to Mashburn,so what this post about Rem 700 bolt handles falling off has to do with expansion penetration tests of a Bitterroot I have no idea. But in usual CF fashions wandering minds seem incapable of sticking with the topic of the thread.

Kind of like little kids with ADD.


As to these tired old conversations about which of the Weatherby and the Mashburn are "faster" it may be worthwhile to think about the history of the two cartridges.

Why, if the Weatherby came first in the mid 1940's,did guys like Art Mashburn develop something else? Why did people like Page and Hagel not latch on to the Weatherby and use the Mashburn instead? Why did Mashburn also develop other wildcats in 30 caliber,much like the 300 Weatherby at the same time? Not hard to figure out...


The Weatherby came first,was proprietary and featured a 12 twist designed for light bullets,and had very long freebore. So if it existed why did guys like Art Mashburn develop their own wildcats similar to the Weatherby,not only in 7mm but 30 caliber and other calibers as well?

It was because they did not want to pay for expensive proprietary brass,did not want to form radiused shoulders(which serves no useful purpose at all and is mere hype), and did not want free bore which, with bullets of the day caused accuracy to suffer. Art Mashburn mentioned this in his load data.

.Plus, then as now, savvy riflemen knew that the LR magic in 7mm rested with the heavy 7mm bullets and the 12 twist of the Weatherby rifles would not stabilize 160,175,or 180 gr bullets. The riflemen of the day were not really all that happy with this arrangement with the 7mm Weatherby, the reason the cartridge was never very popular until the 7mm Rem Mag became available. It took Weatherby a few years to wake up and give their barrels a faster twist and shorten the free bore.

(Even the guys like Les Bowman, Wayne Leeks and Mike Walker of Remington had enough brains in 1962 to give the 7 Rem mag a twist of 9.5 so they could use 150-175 gr bullets, But those guys were experienced hunters and shooters.....not insurance salesmen).

So, the Mashburn was an engineered solution to an engineering problem; designed to seat heavy bullets closer to the lands and still have enough capacity to give a 175 gr bullet over 3000 fps. It is no trick to push them at 3100 fps. with modern powders. 160 gr bullets will easily hit 3250 from a 24" barrel and ,like me,Beretz exceeded that number during load development but backed off and settled on 3200 fps with the same load I use with H1000.To grab another 50 fps is like breaking sticks.

There are today a slew of 7mm magnums out there that give these same general performance levels; the Weatherby, the STW,the Dakota,the LRM,and the new 28Nosler among them.The Mashburn sits about squarely in the middle of these in terms of capacity and a formed case holds 90 gr of water ( the new 28 Nosler holds 93 according to figures I have seen).This is not an accident; it was by design. More capacity in a 7mm bore does not get appreciably more velocity and in many cases will require a longer barrel and heavier powder charges to do so.

The Weatherby seems to hold a couple of grains less; It gets its speeds with free bore and pressures likely in the 65,000 psi range.Even today some smiths cut chambers for Weatherby rounds with standard throats to seat bullets closer to the lands (everyone seems obsessed with this today) and (almost) everyone knows that you can't run Weatherby data for hand loads,and Weatherby factory ammo in a short throated rifle without freebore. You will probably run into pressure issues either way.

So if Weatherby rifles,and freebore,and long jumps into the lands with factory rifles are your thing that's fine.....get a Weatherby factory rifle and be happy. But none of that is a feature I will deliberately build into a custom rifle.

I think in some circles on here, this long jump and not being able to reach the lands is known as a "goat puck",and I agree. YMMV.

For all those scared to death of forming a wildcat,my good acquaintance on here 79S was good enough to show me a source of factory Mashburn brass so I don't even have to sweat the forming process,(which was never really a big deal anyway). I bought 140 rounds of the stuff so I am all set for now(It cost about the same as 7mm Weatherby but not close to $4/round)....I can still make all I want from 300 Win Mag instead of paying $3-4$ bucks each for the boutique chamberings. All this wheel spinning and madison Ave hype, and Art Mashburn gave LR riflemen what they needed in a belted 7mm 60 years ago....hilarious.



Scotty, that BBC shows typical performance and what I've seen from the bullet on animals up to elk sized. I'd happily shoot that combo on anything here,including an Alaskan brown bear.It will make short work of your elk this season.I hope to take the Mashburn with that bullet moose hunting this fall.

Excellent summary, wrap up to now 12 pages of disscussion, and history. Long live the 7mm Mashburn Super! A perfect 7.

Your on another planet..

Bob nailed the Mashburn. I didn't do it cause it is appreciably "better" than a 7mm Weatherby or even as fast as the STW but the cartridge fits very well in a 3.6" magazine box on my Model 70. It was an older 7mm Rem Mag that was my very first big game rifle. Having the reamer run up into the chamber cleaned up any/most of the throat erosion that was there from years of shooting.

Making the MSM cases is very easy. I have been shooting Dober's fireforming load (IMR4350) with 139 Hornady's and 140 BT/AB's. They all shoot very well and run right at 3200 with around MOA accuracy.

The whole works cost me 125.00 for the rechamber job as I borrowed a reamer. So I figured I wouldn't be out of much money if it turned out to be a dud. It's not..

Right now I am working with 175 PT's and H1000.. Everything is looking pretty good at first glance. Just like the 160 AB's did.. A little tweaking should have me sitting squarely in the 3050-3075 range for the 175's. All I was hoping for was 3050, so it met that goal and my reformed Hornady cases are holding up very well. No trimming yet either, nice byproduct..







I did try a little Retumbo I had left as well.. Looks decent as well.





So, all in all, I couldn't be happier. Rifle weighs right at 8lb's 8oz's with 3 rounds in the rifle..

[img]http://i723.photobucket.com/al...-998F-B61D0A9BAB29_zpspyq7fvfm.jpg[/img]

Just to add some more to this.

This is where I ended up with the 175 PT. Pretty happy with it.