Home Forums Hunting & Shooting Custom Rifles & Wildcats 7MM Mashburn Super ????????

RinB,

I have never owned a 7 RM (although hunted with a borrowed one once or twice), but all the bad press about its internal ballistics and the recent published velocities, which seem a little weak, have given me a bad impression of the cartridge and made me want something else (i.e. 7 Mashburn, 7 Weath, 7x61, etc.). I like the Mashburn and 7-300 because if on a hunt and I REALLY needed ammo. I would use 7 RM in them, which would be hard on the throat of either, but could get you out of a pinch. I don't think this would work with the others.

With that said, the 7 RM could be an excellent cartridge for all I know.

If someone can get Dave Petzal to chime in here, he knows where the rifle is and might even contact the owner and get a real measurement. Then all would know.

The neck on the Mashburn is .350" long. There is a cartridge drawing on Steve's pages for all to see. The design length is 3.48" if I remember correctly, so Page wouldn't have used a 3.375 box.

If you are looking at a 7mm/.300 Weatherby just do the STW. For all practical purposes it is the same thing. No up charge on the dies. The extra capacity doesn't get you much. You can shoot 7 Rem in the Mashburn chamber if you get really jammed up out beyond nowhere; you can't do that with any of the others.

Rin-I have both an article by Page and one by Hagel I can send to you if you wish. Just pm me your email. I think that Bob sent you the one by Page the other day?

One of my Mashburns is on a 700 and the other is a pretty gun on an Obendorf and this one will just plain knock your sox off!

Dober

Hagel wrote:

", after a good deal of correspondence with my friend Warren Page, who had just then started to use the 7mm Mashburn Super Magnum, I had Art Mashburn chamber a Douglas barrel for it and fit it to an FN series 300 magnum-length action."

One of my uncles had a 7mm Mashburn and a 10.75x68
both built on Enfield actions. I have never handled
these guns, but have photos of him with them, usually
with a deer. They "disappeared" after he passed away,
and nobody in the family knows what happened to them.

It was Warren Page's scribings about the 7mm Mashburn in the early 1950's that had me get a 7mm Ackley Mag built right after graduating from college in 1957. No one else had any influence for me making that decision, except for Warren Page.
I would have gone with a 7mm Mashburn, except that I had PO Ackley build the rifle; so, I chose his 7mm Mag.

b: To convert a M70 Classic in 300 win mag or 7RM to a H&H length box will require a H&H length magazine box and follower,replace or modify the bolt stop and ejector.If you don't the old ejector will hang over the magazine well,and you can't load the magazine.I used to order these parts from Winchester because I converted a couple of 300 Win Mags to H&H length.I do not know where to get parts for the Classic today.

In a pinch I have drilled out the spot welds on a win mag box, removed the spacer and tig welded the box together. The bolt stop and ejector can be carefully ground to fit with a Dremel.

I remember going in Mashburn's gun shop in OKC with my Dad when I was a little kid.....coolest place on the planet to a twelve year old gun fanatic. Mr. Mashburn was always very kind and patient with a little kid who read the Rifleman, G&A, Outdoor Life and Sports Afield cover to cover. That's where Daddy bought the old M70 fwt I still hunt with. and where I bought my first serious smallbore target rifle...a brand new Remington 521T....wish I still had it.

Very cool Steve, thanks for sharing.

Steve: That is neat....I have never seen a Mahburn rifle.From the looks of pictures of Page's rifle,they were well made.

BWALKER: Yes, you can modify the box and other parts to go H&H length.Not a bad idea even if you keep the rifle as a 7RM.

Bump for a killer round...

Dober

aka:

7em-em Mash-em Into A Stupor

bob - considering the mods. My only question is what I gain over my current 7RM and 26" tube. Anything less than 100 ft/sec seems a waste of time..................

Based on what I have seen, if you long load your 7 mm Rem, the difference is about 100-150 fps. The actual effective case capacity differance is about 3-5 grains. The long neck on the Mashburn gives you loading flexability with bullets re. stand-off from the lands (freebore) that the Rem doesn't have.

Max (63-65 K psi.)with a 175 in a Rem is about 2975-3040 fps. in a 24" barrel depending upon powder, etc. I the same barrel length a Mashburn gives about 3075-3130. YMMV.

b: I have never owned a Mashburn so cannot say;but see docbill's post above comparing the two cartridges.Keep in mind the Mashburn predated the Rem mag by quite a few years,and was likely one of the reasons for the Remington mags' existence,along with Les Bowman's work necking down the 338 Win Mag when it came out.he got non-headstamped 338 cases from Winchester;Fred Huntington put the first rifle together for Bowman.

I have(had) no way of testing pressures other than the typical methods many of us use,but my old favorite(long gone, shot out) lightweight,long throat 7RM put together by Butch Searcy did 3125 consistently with the 160 Partition;close to 3300 with the 140 Partition and 140 Bitterroot.My Dakota gives 3375 with the same bullets.It appears the Mashburn(and the Dakota) will beat these 7RM figures as note by docbill.

I will note I never had a pressure "problem" of ant kind at these velocities.Keep in mind a "throated" 7RM really becomes a 7mm Weatherby in essence;capacities are pretty much the same,and the Weatherby gets its higher velocity from being loaded to higher pressures and the Weatherby freebore.

BTW,the 140 gr,jumping that long throat,shot fabulously in my old rifle,contrary to what someitmes happens.

I suspect a guy could use these 4 cartridges with optimum loads for each(Mashburn,7RM, 7 Weatherby,and 7 Dakota) for a lifetime of hunting and never tell the difference.Page proved that these ballistics with a 175 gr bullet(yes, maybe old school is a very tough combo to beat for soft skinned game of many types,worldwide,coming almost to the performance of a 300 mag in a light rifle,without beating you into next week.

If anyone wants to run simulations with ballastic software, look at a 3100 fps 175 spitzer ( sd .313), Sierra just for fun, compared to a 200 gr. (sd .301) .30 cal. of the same make at 3000 fps. The 7 mm beats it on drop and equals it on energy at 400 yds. +. And no one ever even suggested that a 175 7 mm won't penetrate to the far side of the Moon.

Next compare the weight and recoil of the .300 Weatherby that will have to drive that 200 gr. at 3000+ fps. and think about which you would rather haul all over the toughest elk or goat mountain you can think of!

That was the trade off Warren Page thought of in 1950 whatever when he started talking about the Mashburn and such. The answer was good then and great now. The real issue is that unless you are a handloader and knowledgeable, the 7 mm Rem is grossly under loaded by the various factories and as such is just another 30-06. The Weatherby and Dakota are loaded to potential.

Gentelmen, choose your weapons and HUNT! Merry Turkey to all.

....Indeed....

I'm thinking a Mashburn on a Rem700 with a a really retro bird's eye maple stock in the "California" style would suit my fancy. Strangely those Weatherby stocks have grown on me over the years and they just seem fitting for a cartridge of this era.

I, brother, and freinds have loaded the 7 STW in custom barrels with minimum spec match chambers for deer hunting, to Weatherby pressures, you guys had ought to think about how the picture would change.