7 LRM versus 7mm Mashburn Magnum

[pig ranch deadeye]

The 7mm Mashburn Magnum has about five or six grains more powder capacity than the 7mm Rem Mag. It has a neck that is about half again as long. You can seat the bullets out long so as not to impinge on the powder capacity.

This is about the same advantage as provided by the 7LRMm, a more modern belt-less round. So my question is, which round is better? I say the 7mm Mashburn is better because the case easily can be formed from .300 win mag brass. The advantage is practicality.

What do you guys think? Either round allows you to step up from the 7mm Rem Mag in performance, letting you propel 175 grain bullets at the same velocity as the 160 grain bullets in the 7mm Rem Mag. So gentlemen, let me hear from you. Which round is better?

 

[HARPERC]

C) Similar rifles will produce similar results.

 

[shootallday]

I prefer not to have a belt.

 

[pig ranch deadeye]

I have gotten fat and my belt no longer fits.

 

[laker]

I have a soft spot for the mashburn so I'm going with that. The mashburn is what the 7mm Remington should have been

 

[keithcandler]

Mashburn shoots the 160g accubonds at 3200, nary a pressure sign, 3350 is max.

7RM is 3100 on a 26", 3200 on a 28"...balls to the wall loads with Retumbo, 160g

Will soon find out what a 27" Mashburn will do using Blue bag Winchester brass.

 

[pig ranch deadeye]

Have you ever used Ramshot Magnum with the Mashburn?

 

[pig ranch deadeye]

Mashburn shoots the 160g accubonds at 3200, nary a pressure sign, 3350 is max.

7RM is 3100 on a 26", 3200 on a 28"...balls to the wall loads with Retumbo, 160g

Will soon find out what a 27" Mashburn will do using Blue bag Winchester brass.

Let me know you that 27" Mashburn turns out, please.

 

[pig ranch deadeye]

I have a soft spot for the mashburn so I'm going with that. The mashburn is what the 7mm Remington should have been

That's right. If Rem had made the Mashburn instead of the 7mm Rem Mag, they could have used the same basic 2.6 inch case to manufacture both the Mashburn and the .300 Win Mag too.

 

[archeratlrg]

So here's my dilemma regarding the Mashburn. Had a smith in Oregon rechamber a 7mm Rem mag to the Mashburn Super. He used a chipped reamer so far a bad chamber. Didn't realize it until I had finished my move to Montana and started trying to shoot it it. Took it to a well known G'smith in Helena to clean it up. No problem he says, I have a reamer. So he sets the barrel back and rechambers it. When I start messing with it I realize something is way off. Turns out his reamer must have been reharpened many times over the years. I miked my shoulders and they are right at .483 instead of the Mashburn's .495 so looking for a good smith here in Montana to redo it correctly so I can get to shooting. Any suggestions? If nothing else I'll have OT&G make me a reamer and do it myself. Thanks for any suggestions.

 

[David Emerson]

So here's my dilemma regarding the Mashburn. Had a smith in Oregon rechamber a 7mm Rem mag to the Mashburn Super. He used a chipped reamer so far a bad chamber. Didn't realize it until I had finished my move to Montana and started trying to shoot it it. Took it to a well known G'smith in Helena to clean it up. No problem he says, I have a reamer. So he sets the barrel back and rechambers it. When I start messing with it I realize something is way off. Turns out his reamer must have been reharpened many times over the years. I miked my shoulders and they are right at .483 instead of the Mashburn's .495 so looking for a good smith here in Montana to redo it correctly so I can get to shooting. Any suggestions? If nothing else I'll have OT&G make me a reamer and do it myself. Thanks for any suggestions.

I have a 7mm practical reamer which is very close to the mashburn super mag. It measures .490 at the shoulder. One from Kiff measures .495. 30 degree shoulder. I think but not sure that the practical is longer in the head to shoulder than the mashburn.

 

[laker]

4d reamers carry a mashburn reamer that can be rented

 

[laker]

My newest mashburn build. Bell and Carlson ti takeoff stock, defiance anti action, lilja barrel

 

[gregsjt]

The LRM is a perfectly designed round, there are no compromises. No rebated rim like the ultra mag or short mag cases, no belt, generous neck, and a over-all-length that allows seating of long bullets at standard long action lengths. The only problem was hornady made brass that was a little to soft and couldn't hold up to multiple firings. Plus Gunwerks was the only source for said crappy brass. Now, ADG is making the brass for Gunwerks, it's probably to early to tell if it will make a big difference, but one would think that it will be much better than the hornady brass. Also, you have lots of brass makers jumping on the 300 PRC wagon, including Lapua, it wouldn't be too hard to make 7LRM brass from 300 PRC. If you're considering a wildcat as the other option, I think the LRM wouldn't be a bad choice considering all of the above.