7×57mm Brass Strength?

[Glenn Powell]

This is gonna be really out side the box thinking so please bear with me. The 7×57mm brass is .22 longer than 308 based cartridges which means more powder room. Can it handle the higher pressures achieved with the 308 case?
The magazine length on the action I am going to build my next rifle on is 2.995, the Hodgdon manual shows an Col of 2.88-3.000. Now here's the deal. I am going to have three barrels for this rifle, 6mm, 7mm, and 338. If I "AI" the 7×57mm the velocity should really come up. If I neck it up and blow it out for the 338, I should be able to utilize the full potential of the magazine and get really close to the 338-06 performance, and better than the 338 Fed. Am I on the right track in my thinking I can have my cake and eat it too with this case as a base for which to build my "Ultimate Rifle"?

I have mulled over the 308/284 cases for a while now. My 338 barrel shipped today so I am getting ready to order reamer(s). Its getting down to the "$#π€ or get off the pot" stages for this build. I am not intimidated by necking up, down, turning, or fire forming, and kinda enjoy doing it. The 6mm barrel is spoken for, so don't bother with that one.

 

[areaone]

You are missing the obvious. 8x57mm the old WW!! German mainstay. The case mouth is already close to 338 and if you want Ackley just blow it out, not sure what you can achieve by doing this due to shoulder, altho there are better selections of 338 bullets than 323, I think you are so close to reinventing the wheel that you are not gaining much.

 

[Glenn Powell]

Its the 338 bullets I need since the barrel is in the mail. I thought about an 8mm, but due to bullet selection and Hart dose not do 8mm barrels, the 338 is what I have to work with. Velocities for the old 7 & 8×57mm boys are lacking, effective yes, just lacking.

The case mouth is already close to 338 and if you want Ackley just blow it out, not sure what you can achieve by doing this due to shoulder.
What about the shoulder?

 

[areaone]

Use a 8x57 case and open to 338. Simple and no stress on the neck, but look at the shoulder on a 8x57 and very little if any shoulder to form to an ackley 40 degree shoulder. Not much to gain with an ackley, maybe 50 FPS. Hardly worh while IMO. Custom dies, reamers and other expenses seem not worth the gain. For reference, look at the Nosler #6 manual, compare the 30-06 to the 30-06 AI, note that you gain very very little, then look at the 8x57 and compare to the 338-06. Then if you AI the 8x57 what is to gain, extrapolate the 06 to 06 AI data and make the decision you are comfortable with. Like the 7x57, the 8x57 was "way ahead of its time" compared to current "new" chamberings, i.e 338 Federal and 338-06 and the like. Just seems when a caliber is a european native, MM, it just is not as popular a Home grown model. 7x57 compared to a 7mm-08, 6.5x55 compaered to the 260, etc. The venerable 6mm Remington is nothing more than a 6x57, Popularity would have been limited if it were named the 6x57 as opposed to the 6mm Remington(home grown). What do you think the 257 Roberts is, Nothing more than a 25x57. Same with the 308 case on .243, 260, 7-08,338 federal, 358. European or Home grown, not much different.

 

[CatShooter]

The 7x57 case will handle any pressure that the 308 or other modern cartridge will.

It is loaded light from factories because it first appeared in 1893, and there are a lot of old weak rifles still around.

 

[Glenn Powell]

So I can run it hotter, great. Thanks Cat.

I did a little home work last night. I agree with ya, tomato/tomoto when it comes to the 57mm and 08. Just minor differences at a glance. I am going to have to buy a reamer for the 338 barrel regardless if its a 338 Fed, 338-284, 338×57mm, or any of these Ackley Improved. I think with the action length that I have, the 338×57mm would be a better fit, with more rounds in the magazine, and smoother feeding than the 284. The federal? Too boring, sorry.

 

[xpilot]

Years ago I built my hunting gun , a 7x57 AI. Awesome rig. No pressure problems with stiff loads. Took everything from coyotes to elk. Never regretted the 7x57AI. Good luck with yours.

 

[Barlow]

7x57 ammo in the U.S. is loaded light because it may be fired in old weak (they say) military rifles. That may be true, but in Europe Norma loads the 7x57 much hotter. I have a Ruger 77ts 7x57 and I have used loading data from Bob Hagels books. I won't say what the loads are, but I have never had a problem with them in this rifle. I was going to AI it, but it kills so well the way it is, I see no reason to do it. my 2 cents. Barlow

 

[7x57 Shooter]

The 7x57 is my all time favorite cartridge, I have had them all, 7mm-08, 280 Remington, 284 Winchester, 7mm STW, 7mm Remington mag, 7x61 S&H.
I prefer the 7x57 Mauser in the Mountain Rifle that I have owned for the past decade.
Easy to reload for, pleasant to shoot and devestating on game.

 

[Joe Maisto]

7x57 Shooter,

I was pleasantly surprised at your knowing of the 7x61 S&H. That cartridge goes back to the 60's, along with the .308 & .358 Norma mags. They may have been the forerunners of all the big stuff we have today. It has been said the 7MM is the finest bullet designed for a variety of reasons.
I believe it as well.

 

[a1712]

7x57 Shooter,

I was pleasantly surprised at your knowing of the 7x61 S&H. That cartridge goes back to the 60's, along with the .308 & .358 Norma mags. They may have been the forerunners of all the big stuff we have today. It has been said the 7MM is the finest bullet designed for a variety of reasons.
I believe it as well.

I think the .375 H&H in 1912 and .300 H&H in 1925 started the stuff we have today. Brian.

 

[Joe Maisto]

A-1712,

I believe you are correct and failed to think about them. On the other hand, those cartridges were extremely lone with a belt. We have gone the other way , a .284 in a Win. 88 as an example. I've had 3 of these. They were my meat gun for deer and such , more so than my .760 .35 Whelen I had chambered by "Boots" Obermeyer in the early 60's.

 

[wapiti25]

If you are going to buy a reamer anyway why not go with the Ackley version, 100 ft/sec more. The shoulder on the 7X57 and 8X57 are not the same but they are close. You can make the brass you want out of 30-06 if need be but it will have to be shortened some.