Home Forums Hunting & Shooting Custom Rifles & Wildcats Here's my 7mm Mashburn, show us yours!

Since we are talking about the 7-300.

I've had her for a couple weeks now, playing around with load development. Looks like she is going to shoot very well!



Gunsmith: Kevin Weaver
Remington 700
Echols Shrike stock, edge shell, regular fill
Lilja barrel, 9-twist
TriggerTech trigger
Sunny Hill bottom metal
Talley standard steel mounts (Signature Bases and Screw Lock Rings)
All metal Nitride coated

Kevin did all the Shrike stock fitting, put in the nice sling studs, replaced the barrel. He did an excellent job!

She's the one on the right...the other Mashburn is the one on the left. Also a Kevin Weaver.

Details on the wood stocked Mashburn?

That's a beauty!

Thanks!

Wood stocked Mashburn

Rifle details:
Gunsmith Kevin Weaver
Wood from Roger Vardy in Australia
Stock and metal work done by Kevin (I think he sent the bolt out for bolt checkering)
Borden Timberline Magnum action (SS steel)
#2 Krieger, 8-twist (CM steel)
Dakota bottom metal
Nitride coating by H&M (Kevin sent it out for coating)
Talley Signature bases and Screw Lock rings
Leupold 6x42 LRD

More pictures of her here. https://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/14295738/1

The one on the left is gorgeous !

Nice!

Nice rifles. What are the barrel lengths?

25 on the wood stocked rifle and 24 on the Shrike

Joel,
Great pics and good looking rifles!
Any idea what the shrike with edge shell and standard fill weights? And what is the advantage of this combination (weight savings - anything else?)
Have read that you can do edge shell/standard fill or regular glass/edge fill, just curious as to the why. Any change in recoil perception that you notice from your other legends?
Really appreciate it - and love your write ups and pics!

Damn nice rifles Joel, you should christen this the 7mm Mashburn thread and have everyone put up pics of their rifles.

Gunner - great idea!

I’m in!

Change the thread title to something like "Here's my 7mm Mashburn, show us yours!

Thanks!

I haven’t taken it off finished to weigh it but I would guess around the 32 oz mark based off weighing it before it was finished. I think it was around 25 oz before finishing/without recoil pad.

As for the advantage of the edge shell, I like it because it’s a very stiff shell. The standard shell is good but pretty easy to flex in my opinion. The edge shell you just can’t bend.

D’Arcy Echols is the brains behind the standard fill. He explained to me that he has noted the Edge shell/Edge fill to result in rifles that are “finicky”. He said he has seen more reliable performance shooting wise with the edge shell/standard fill than the edge shell/edge fill. Anecdotally I noted I have a 30-06 with edge/edge combination that is finicky—what it likes it will shoot lights out, what it doesn’t like it will not shoot no matter what you do.

I can’t speak to the recoil reduction compared to the Legend. I’ve not shot a Legend, though I’ve handled a bunch of friends’ Legends. I can say the Shrike definitely handles recoil nicely and the geometry of the stock makes handling the rifle through the recoil pulse very well. My buddies with Legends say the same. Echols really has some great stocks and I wouldn’t hesitate to get either. It did take me quite a while to get the Shrike.

Count me in as another Mashburn user. Mine is basically a duplicate of Farese's gun, built by same builder using pretty much the same parts with the exception of the barrel.Mine has a Bartlien and his a Krieger, both in 9 twist. I had another one but eventually rebarreled it to 7mm Rem mag. Having 2 wildcat chambers cut from different reamers is something to avoid, trust me on that!
Mine is like Beretz's gun in that it has a long throat, the reamer was ground specifically for 175 Noslers and like his, it shoots very well with them but not so good with lighter/shorter bullets. I've had another reamer made to the same body spec's but with a shorter throat and it will be used this year on a new barrel to be installed on the gun.
This rifle has taught me a lot about cases and how they match up with sizing dies. My original Redding sizer was apparently made to a smaller case dimension in several critical areas and it over worked the brass a lot. This caused excess pressure even with moderate loads and I trashed many cases before finally having a custom Whidden sizer made to match my chamber. Since then life has been much better and I'm finally getting the speeds I'd hoped for, all with good case life. If I were to give any prospective Mashburn owner a bit of advice it'd be to have a custom die made from your brass, it's just a crap shoot to buy a standard die and expect it to fit your chamber correctly.
From talking to various folks, it's reasonable to expect 50-75fps more velocity than a Rem mag will offer from same barrel lengths. Sometimes you get a "fast" barrel and can see more than that, but in general I've found that to be close. My 25" Rem mag pretty much equals my 24" Mashburn, so if case forming, then fire forming, then reaming donuts and buying custom dies doesn't appeal to you, just put a 25" or 26" barrel on a Rem mag and be happy! No elk, deer or moose will ever know the difference. But if you're a gun nut and like a bit of nostalgia to go along with having a very well balanced cartridge, the Mashburn is definitely worth having.

Edit. Mine has a Legend stock with Edge shell/fill and it is a bit finicky as to loads. I also have a 300 Win mag with same stock and it exhibits the same tendencies.

The one on the right is GORGEOUS!

Great post Joel. Looks great. I’ve got Matt’s Masher at my house and think I have a picture of Bobs as well. I’ll get some pictures posted.

Mine is cut with the same reamer as John’s. I also have custom Whidden dies and echo what he has said.

Hell of a deal, I'm afraid if I send anymore pics for beretzs to post the next time he's driving out West to elk hunt he's going to stop in here and kick me in the balls ; ]

Pathfinder, who was the smith?

Send em Gunner...

Great! Thank you Sir, you know, I should verify the Mashburn at 100, then twist it up and see what it will do at 900, bench is still over in the second pasture, iirc, the 160 AB leaving at 3220 is still packing near 1800 fps at 900 yards, that will be fun, I have a phone call after while, then i'll shoot and take some pics!

Thanks again Big Buddy!

Bill Leeper

A fellow Remington lover!

That's my new one.

1-8 Bart
Legend EDGE Shell - Standard Fill
P64 Magnum action
3.650 box
Blackburn BM

You guys are going to end up making me reach for my folding money.

This was Ol' Nasty.. A M70 Push Feeder I had Matt's reamer shoved into. It was my original BG rifle and to be honest my new one doesn't shoot any better.

B&C Stock
3.650 Mag Box
Shortened Bolt Stop

It is still out there in the hands of my old goat hunting partner, and still slinging 160 AB's with authority. It's a great old rifle for a pusher..

Send them when you want!

That’s a darned fine rifle. Every time I see it I can just tell how well it works and looks. What’s yours weigh scoped?

Kevin will get you one spun up in no time buddy. I happen to know where a great reamer is as well. It’d take the wondering right outta which rifle you’d have to take for that Grizz/sheep hunt

7lbs 12 ish ozs

I need to put mine on a diet next time it gets rebarreled. That’s about darned perfect.

You guys are not helping my addiction. But I think I need one.

Getting the right reamer means a lot. I’ve had a short one and long one. The short one shot everything well, the long one does great with the heavies and both got the same speeds. I’ll do a short throat next time.

Well, I found out a 200gr Lehigh Penetrator from a 45 ACP will smoke a garden bunny just out the gate, verified 100 yard setting, did little tracking test, 4 left, 4 right, two up, two left, two right, two down, the little NF SHV is going to be a good hunting scope, I pissed around too much waiting on dusk to shoot at 900, phone went off again and used my time.

I'll give 900 a go tomorrow before the rains get here.

Don't think I haven't considered it.

Might go 28 Nosler just for the ready made brass.

It's a heck of a cartridge nyrifleman, I went with a 25 inch 8 twist #3 Brux, bet it would spin 180gr ELD's or 190gr A-Tips up good and tight at near 3000 fps.

Beautiful rifles guys! How does the recoil compare to a 300 win?

About the same to me ejo, a 160gr AB at 3200 or a 200gr Partition at 3000, both in roughly 9lb all up rifles.

Yeah, that is a serious pro. Until ADG started making brass I wouldn’t have hitched it with the Nosler brass but the ADG brass is very good brass.

I think the beauty of the Mashburn is a rifle like Pathfinder’s at 7lb 12 ounces all scoped and ready to hunt. My goal was 8lbs or under. I believe next time around I’ll be using a less beefier barrel and get some action skeletonizing to drop the ounces.

My answer to weight was a Brown Precision pounder stock and no bottom metal. I also speced all the graphite fiber in the forearm that was possible for stiffness.

By doing that I could go up to a #4 Lilja barrel for stiffness and Leupold 6x36 LR. All up weight is 7.5 lb with a nylon sling and no ammo. Shoots 175 gr Sierra at 3075 into .75" 5 shot groups. Zero 3" high 100, on at 290.

8 lbs or less scoped is my goal as well.

Deciding between a big 7 or a 300 Win Mag.

I know Bob always preferred the big 7.

I still have a pile of 7mm Dakota brass onhand, but that would involve work on the bolt face, etc.

Mashburn or Nosler if I go with a 7mm.

I do have a 7mm Rem Mag I built on a M70 classic edge. Sub 8lbs with a Swaro Z5 3.5-18 in Talley Lightweights. One of my "core 4".

Shoots the 160 Accubond VERY well at 3100, so maybe what I'm looking for is already in the safe.

What load do you use to get 3100?

I like the 7mm's myself in a sub 8 pound rifle they aren't real unmanageable with the top end loads. You're current 70 is pretty danged close to perfect in my opinion if you like it. If It shoots well now, it isn't going to shoot less well as a Mashburn either. It's almost cheating to stick a 3.6" mag box, shorter bolt stop and rechamber a 7mm Rem Mag to see if you like it. It is what I did for my first one and I decided I liked it enough to have Kevin Weaver build me one I really liked.

The Mashburn is exactly like John55, Joel and Gunner describe it. For my first one I used plain old RCBS FL dies and simply ran Hornady 300 Win Mag cases into the die and when I pulled them out they were 95% ready to go. I used Dober's load of 65-67 grains of IMR4350 with a 139-145 grain bullet and formed all of my brass. My only issue was once neck donuts started appearing. Bob never got them, Gunner hasn't ever got them, but with the 3 Mashers I have worked with, I got them. It is super easy though, a quick ream with an electric drill and they are gone forever.

I got the Redding dies when I got the 2nd rifle and that's all I have used to this point. John and Joel have the Whidden dies made for their chambers so they have gotten away without donuts thus far.

Dober's had 7 barrels on his Mashburn over the years and doesn't believe in the donuts and he's filled arks full of elk, bear and deer with his with 120 Barnes through 175 Semi Spitzer Partitions.

I can't remember if PF76 has dealt with donuts or not in his gun, but honestly it isn't that big of a deal if they show up.

The beauty of the Mashburn is ANY of the 300 Win Mag cases will work really well. WW used to be the gold standard. I used alot of Hornady, but has been using the same 50 RWS cases I formed back in 2017'ish. God knows how many loads of 175's over 83.8 grains of RL33 I have on them, but it is going on 6-8 firings, I anneal them everytime and they just won't wear out. ADG now makes 300 Win Mag brass which is probably as good or better than RWS so the amount of great brass makes the Mashburn pretty appealing to me and its just outside the ballpark of a 28 Nosler. I also don't think it needs a barrel longer than 24" myself. My old Winchester that was rechambered was just as fast as this Bartlein and just as accurate with almost the same charges of powder.

I just finished up load work for my cousins 28 Nosler and I used H1000 for 175 Partitions and averaged 3110 for speeds. I could've used Retumbo or RL33 and probably gained 100 FPS but on that one, I think it needs the 26" barrel to get those speeds, it recoils more, and is a bit heavier rifle and you lose 1 round typically in the belly. Any of our Win Mag Classics will feed and function like they have eyes with the Mashburn case, while a 28 Nosler will be more work to get them to feed and function that way.

Sorry for the babbling, just my thoughts on it.

300 Win Mag with a 1-8/1-9 barrel is pretty easy if you don't want any of the extra HorseSh*t if it is set up to seat the longer bullets to maximize case space. John55 has worked with 3 of Weavers recent 300 Wins and can chime in with his thoughts on them to give you an idea of what he is getting.

Here is Gunner's Mashburn Super





And his latest kill with the Glock...

Mrs. McGregor’s Pie!

LOL, Thanks Big B, that little NF tracks pretty true huh? waiting on the rain to clear to try for 900, that damn rabbit was eyeballing Wifes garden just outside the back gate, the 200gr Lehigh over penetrated, look at the hole in the ground.

No pie Mr. Douglas, too late in the year for eating, chunked it over the fence, the Rotts were playing stretch arm strong with him when I fired up the ATV and left ; ]

Yeah, you’ve got a killer set up as well Gunner.

Careful now fellas, we’ll be pushing NYrifleman over the edge here soon

Thanks, and Yes, he'll be flexing some plastic or rolling ink in no time!

It's either 66.0 or 68.0 7828SSC, I'd need to check my notes. Shot over my LabRadar chrono.

I'm going to load some 175 Partitions over Retumbo and RL26. Should get 2900+ I would think.

If anyone has a good load, chime in!

If the 175 shoots well with acceptable velocity, the decision may be made for me.

You know, I had a Masburn in the safe at one point.

But that 7mm Rem and the 7mm Dakota I had in the safe at the time made it redundant so I flipped it before I ever shot it.

If a 7lb Mashburn on an M70 action, which is proven shooter came up for sale here I'd be hard pressed not to jump.

Beretzs, not babbling - I'm enjoying the conversation of like minded individuals. Carry on!

Looks like a beautiful thing to spend your money on.

Welp, I found the limit of a 160gr Accubond with cannelure at 900 yards, didn't take a pic, too embarrassing, those things river boat paddle wheeled themselves into a 3 shot 24 inch group, that said and learned, I moved my bench back to it's old spot and had at the 500 yard gong, in crazy winds, three went into a bit under 4 inches, that I can hunt with, I don't know where that bullet really came unwound, but it's somewhere North of 500 to 900 yards.

Need to experiment with big 180 ish grain bullets for real longer range shooting/hunting, the 8 twist and 3200 fps really walked that fine hunting bullet, the same bullet without cannelure may have flown better, pics on the way soon.

Appreciate the response Joel.
I wonder what it is about the edge fill that would make the rifle more finicky? I suspect it would be more than just weight, as the weight differential isn’t really all that great.
Having said that, I appreciate you posting the blank weight of your edge shell/standard fill. I picked up a Legend standard shell/mag fill on here a while back for a planned 375 build; that blank weights 35 oz (!) and I’m starting to wonder if I really want to be that heavy on the stock ...
Your experience with the shrike should translate well to the legend, as they are the same pattern. How long was it getting the shrike if I may ask?

I'm one of the few who doesn't care for the ergonomics of the Echols Legend.

Much prefer the McMillan Bridges.

Waiting on an Edge for my RUM.

Pathfinder,

That's a nice looking build. What are the particulars of that barrel (length. contour...)?

FWIW - I just weighed an Echols legend edge shell, standard fill I have and in its out of the mould and unfinished state it weighs 28 ounces.

My last 2 Legend blanks were all Edge and weighed 25oz each. My latest blank that is Edge shell and standard fill weighs 27oz. D’Arcy has told me on several occasions the blanks have become heavier since inception. Early all Edge blanks weighed 19-20oz.
IMO, the reason an all Edge stock can be a bit finicky is due to barrel vibration/harmonics. I’ve not seen it in standard calibers like 270 or 30/06 but once you get to 300 mag levels it’s more of a possibility. For a 338 or larger I use magnum fill. A bit of extra weight doesn’t bother me as it helps with the recoil.

I also don’t mind the extra oz of standard fill weight.

Interesting to hear I’m not the only one with edge shell/standard fill. Must be a good idea!

Thanks. It’s a 24” #2 Douglas

My MSM is heaviier than Pathfinder’s and Farese’s, in spite of virtually identical components. With it’s all Edge stock and 6x36 scope it’s just under 8.25 pounds. My 300 Win mag at same weight is much more of a handful off the bench. 175s at 3000 are no match for 200s at 2975.

I just double checked the weight.

That's a dandy Pathfinder, some really nice rifles in this thread, too damn bad we cant all make a hunt someday using these Mashburn Supers!

Nice rifles all! Don’t have a MSM, just the standard RM. Mine ended up like John55’s though at 8.25 loaded using the same formula shown over and over in this thread.

I too have noticed that McMillan’s fill weights seem to be increasing - not a fan of it either! I’ve got an edge shell/magnum fill at 40 ounces and a Edge shell/ edge fill that weighs 28 ounces. Liked when ordering an Edge meant somewhere around 22-23 ounces. I will be trying something else going forward like the Pound’r. Feel like the McMillans should have gotten lighter over time, not heavier.

Kansas in honor of Bob!

I'd build one for that.

Dang right Sir, i am in, whenever, wherever.

Here is RickF's 7 Mashburn.

Dober's main critter getter!

My old Mashburn the old man recently put into a Pendleton Composite stock..

Wherever fellas, I am game for about anything. That's be cool as all get out.

Pretty cool to see all of these Mashburns coming to the surface with this thread.

I'll get a picture of Matt's Mashburn, which looks just about like PF76's, but the bolt is on the correct side

Hey now. :-)

I'd bet if you get 3100 with 160 Accubonds you'll get near 3000 with the 175's. I love my Mashburn but a good 7 Rem Mag sure is easy and alot less money!

Gunner sent these from his 500 yard outting with his Masher and 160 Accubonds.. Hard to hate that!

Hey Thanks big Buddy, shooting dew North into a crazy [12-15 mph and gusting] wind out of the E/SE, dialed a little wind and let her fly, I have to believe a bullet without a cannelure would be easier to steer, hoping one of you guys will correct me if that's wrong.

I've noticed some are giving build specs, here's mine:

Pre-64 M-70 H&H magnum action
Factory trigger slicked to a tic under 2 lbs [zero creep]
8 twist #3 Brux, 25 inches
Pillared and bedded into a McMillan Super Grade stock, standard fill
NF SHV 3-10 standard duplex
S&K bases and rings
Magnum para-cord sling by HillhamHawk right here at the Campfire
Complete build by Redneck, also here at the Campfire

Those bullets were ordered as seconds from SPS, and for fire-forming only, I found the load too accurate at 100 yards to waste and add undue wear to my barrel/throat, guess no too bad for a standard hunting weight rifle/barrel, will certainly work for 500 yard big game hunting.

Great build Gunner.

It is odd the 160 Accubonds went wonky at you at further than 500 though. Be interesting to see what happens at 100 yard increments.

Thank You, Yes, may be something to do with twist/speed or just those goofy winds, do you think the cannelure had any role in the silliness?

I don't believe so, especially if they are holding tight at 500 I can't see them just going nuts at 900. What sorta speed is it sitting at 900? I gotta think your 8 twist has them plenty stabilized.

10-4, still packing around 1885 fps at 900, may have been those crazy winds, you can see all the peppering on the right side of my gong out practicing in 30-40 mph winds, crazy stuff man.

All that said, I bet a 180gr ELD leaving at 3000 fps will shoot like a house of fire at 900.

If I was going to try one, I'd be inclined to try the 180 Scenar myself. I know 30338 on here has done real well with them on elk and he puts up plenty of proof they'll smash stuff pretty hard and man, they aren't picky about shooting excellent. I should grab a box and just load them up and see what happens on the Mashburn. They aren't 180 ELD sorta BC but I think they are .660'ish which aint too bad either.

Nice, Thanks for the hit, and yes, I've seen what scenarshooter has done with the little scenars, same but bigger cant hurt.

That's what I am thinking.

I know Dober has some 180's but I haven't seen him break them out on the range yet through his Masher.

Here are a couple shots of Page's Ol Betsy that was for sale a few years ago.. I was hoping Bob would snag this old devil, but it went to another home.

I loaded some 175s up over RL26. Waiting for the range to reopen.

Excellent, I am looking forward to seeing that work. I haven't ever found the 175 Partition to be hard to get shooting. I used to use RL22 and the 175 Partition in my old 7mm Rem before it became a Mashburn for around 2950 and it was accurate, but Bob got in my head and told me if I like that, I'd like the same bullet moving a 100 FPS faster!

He weren't wrong!

If RL26 doesn't perk I'll give Retumbo a go.

I'll be happy with 2950 or better.

I'd bet money that 7828, H1000, Retumbo, 26 or a few others, and maybe RL23 if you can find that will get you there.

Roger that, a lot of good choices to stretch it out with, i'll be plenty happy to hunt with these 160 AB's till they're shot up, may look at something different then, LOL, Ol Betsy looks like a cool piece too.

Damn Fed-X truck ran while ago, just got through planting three rows of beans, my damn back is killing me, each bean seed one inch deep, three inches apart with rows two feet apart, AYFKM? , the things we do for our women!

As a rifle looney issue I understand the appeal of the 7mm Mashburn, but if I needed more than a 7mm Remington magnum in a Remington 700, I would go get a 7mm Weatherby in a Weatherby MK V. Let the flaming begin.

That is the easy way if you like Weatherbys and freebore! Matter of fact, I have used a bunch of 7mm Wby data to get started with the Mashburn.

I am not that familiar with the 7mm Mashburn ballistics, what does it actually gain over the 7mm Weatherby? I'm not trying to be argumentative I'm just not that familiar with the round.

The Mashburn has no performance advantage over the 7 Weatherby, or 7 Dakota for that matter. The case sizes for all three are just a touch bigger than the 7 Rem Mag. I consider 7 Weatherby data as a max velocity for the Mashburn. Amazingly 7 Rem Mag max charge loads in my Mashburns usually outperform 7 Weatherby book velocities.

The advantage of the 7 Mashburn over the 7 Weatherby is brass availability. There are several sources of high quality 300 Win Mag brass and less availability, at higher cost, of 7 Weatherby brass.

But if you are willing to get the 7 Weatherby brass it’s a darn good round. Same as the 7 STW (brass availability), 28 Nosler (one source of brass, availability), 7 RUM (availability), 7 Dakota (one source). They are all good rounds.

Then there’s the wildcat thing. Advantage or disadvantage depending on the person.

I understand the brass availability issue, but in the age of ordering brass on line I don't think that it's as big an issues as it may have been in the past. Another point in favor of the Weatherby is while it doesn't matter when hunting in the United States, when hunting overseas, other countries customs people may want the ammunition head stamps to match the markings on the rifle barrel. No I agree that the cost issue between 7mm Weatherby brass and 300 Winchester brass is real, but considering the cost of assembling a custom chambered wildcat rifle it's a bit of a reach for my sense of logic but it is a rifle looney thing.

You aren't wrong at all with any of your points and if you are concerned with any of them a standard Wby is pretty much your man.

Some of the best Mashburns out there are rechambered 7 Rem Mag's to be honest. For a 100 bucks (to rechamber) and a set of dies you are into a Mashburn. The Mashburn gets speed from maximized case space while the Weatherby dotes off of freebore. It's a pick your poison sorta deal. No wrong answers just different ways for getting up the hill.

Beretzs, you are correct, I was thinking of having the rifle built from scratch, I didn't consider rechambering an existing 7mm Remington. In that case it's just the cost of rechambering ($100) because the cost of the dies is a wash, Mashburn or Weatherby.

I recommend that to anyone that just wants to try one out. A quick rechamber on a 700 is really good since you can seat bullets where you want them. A 70 needs a 3.6 magazine and a shortened bolt stop.

A reamer like Matt Hoffman’s or Dober’s would work well in a short magazine though.

I have a 700 CDL SF in 7 rem mag. THe reamer will clean up the chamber on that gun? If so I am interested.

Oh yeah, easy peasy. My old one I pictured on this thread has ALOT of teenager hand loading learning shots with H870 through it and 18 years extra on the barrel. Once the smith took it back and thread and rechambered it, it was like a new barrel. I was blown away how well it shot as a rechamber.

Thanks for that info. It has flutes so they probably have to index those as well.