7mm Mashburn Super Magnum

[SJB358]

It's set up with no throat. I figured bullets wasn't getting any shorter in the future so I wanted to be covered. So your smith could set it up how ever you wanted.

Nice. Makes a ton of sense. Mine was built to seat a 160 AB right at 3.603". Ends up being perfect as the working load sits at 3.550" COAL.

Your reamer is definitely the better way to skin a fish.

 

[BF375]

You've got me thinking of rebarreling the 300 Weatherby to 7mmMSM with the way yours is working.

7mm-300 Bee?

I think that might be too much of a good thing Fotis.

The 7mm/300 Weatherby would, of course, be similar to the 7mm STW. Both are pretty much based on full length 300 H&H brass blown out and necked to 7mm.

Actually, both Art Mashburn and Bob Hagel worked with similar 7mm cartridges,Hagel the 7mm/300 Weatherby,and Mashburn with the 300 H&H left full length. Mashburn found that the full length cartridge didn't deliver much, if any more velocity than the slightly shorter Mashburn Super.

Hagel found basically the same thing with the 7mm/300 Weatherby. As I recall, it showed a slight velocity gain only with the 175 gr bullet. I have read that Hagel felt it was not worthwhile in a 24" barrel. This parallels what I have found comparing the 300 Win Mag and 300 Weatherby when both are used in 24" barrels,and bulls are seated long in the 300 Winchester.

Both found the slightly shorter Mashburn Super case to be more efficient; the reason Mashburn called it the "Super".Of course this was with powders of the day; but any advantage gained by modern powders would benefit any of these cartridges.

 

[DrMike]

BF375,

Welcome aboard. Pleased to see others joining in the fun. You appear reasonably knowledgeable about Hagel and Mashburn's efforts, and that insight is always appreciated.

 

[BF375]

Thank you DrMike. Nice to be here!

 

[SJB358]

Thank you DrMike. Nice to be here!

Welcome aboard. Anyone that can spread the Mashburn gospel like that is good in my camp!

I have probably read the Hagel article 30 times.. It's tough being a looney! :lol:

 

[BF375]

SJB358: Thank you as well! Very good thread here.

The 7mm Mashburn Super is still a great cartridge,even by todays standards.

The new 28 Nosler sounds like a real bomb,and is another in a very long line of 7mm magnums we have to choose from today.

 

[SJB358]

SJB358: Thank you as well! Very good thread here.

The 7mm Mashburn Super is still a great cartridge,even by todays standards.

The new 28 Nosler sounds like a real bomb,and is another in a very long line of 7mm magnums we have to choose from today.

I agree with all of that. The Super has been an excellent cartridge to work with and really is my favorite I have played with so far because of the ease of use...

Probably need to get another barrel on the way, having too much fun with the current one.

 

[Leslil]

I do like my Brux. I'm thinking that I need a 6.5 1-8 #2 and a .284 and a RAR .308
On second thought. With $1800 I could buy every flavor Ruger and just throw the away when there done.

 

[SJB358]

Shot the MSM a little yesterday. The fireform load with the 139 Hornady, 65 grains of IMR4350 always seems to shoot well.



Then I shot a handful of the 175 PTs.



I also put 2 140 Swifts and a 140 BBC threw it as well. Not awesome but I believe I could hunt with it.



Now I've gotta decide if I wanna run the 175 PTs or 160 ABs for elk this Fall.

 

[DrMike]

I do love the 175s out of these big sevens. The bullets, irrespective of make, put a genuine hurting on game.

 

[SJB358]

I do love the 175s out of these big sevens. The bullets, irrespective of make, put a genuine hurting on game.

I would imagine so Mike. It runs about 3050-3060 depending on the day. It seems like a hitter of a load. For the cow elk we will be hunting this year I'm almost half tempted to try the 140 Swifts/BBCs. Both of those bullets at 3225 or so shouldn't give much guff on a poor old cow... :lol:

 

[DrMike]

If 140s out of my .280 will down a cow elk (and they will), you can be certain that a 140 Swift or BBC will topple a cow. Good stuff there.

 

[SJB358]

I know Mike. I guess I'll add the 140 Swifts to the list of loads to try for this Fall!

 

[IdahoCTD]

I'd take what shoots the best as all of them will kill a elk

 

[SJB358]

I'd take what shoots the best as all of them will kill a elk

For sure Nathan. Too many options and not enough hunting.

May use the 175's for elk, the. Switch over to the 140's for deer and black bear at home.

 

[archeratlrg]

I haven't tried Retumbo with 160's but I think it could push the them a little faster than H1000 can. I know I get just under 3100 even with 175's and Retumbo. I just didn't have enough of it to really work with, so I stuck with H1000.

I'll be watching your RL22 and 150 loads.. They sound real good.



I can't wait Mike. Its functioning well and the accuracy seems pretty good as well. Really thinking it'll be a nice rifle in the open country.

Have or anyone else you tried the Mashburn with Re 26?

 

[SJB358]

Have or anyone else you tried the Mashburn with Re 26?

I have, it works about like H1000, 7828, etc. It's a good one if that is what you have. 3150-3200 from 160's and 3000-3050 with 175's.

 

[archeratlrg]

I have, it works about like H1000, 7828, etc. It's a good one if that is what you have. 3150-3200 from 160's and 3000-3050 with 175's.

What start load do you recommend?

 

[SJB358]

What start load do you recommend?

Which bullet are you wanting to start with?

 

[archeratlrg]

160 gr AccuBond or Partition or 175gr Partition although I have a lot of 150 ABLR's and 175gr ABLR's.