First Mauser project-Chamber pressure

Spaz · Dec 17, 2012

So I'm starting my first Mauser project, and I've got a few questions about chamber pressures and if I may be looking at the wrong caliber for my build. The action this gun will be based off of is a M48 Mauser. Why? Well this one is coming to me super cheap.

First off, what is the maximum chamber pressure for the M48 action?

Also, after looking at it the first time, it appears the .30-06 cartridge will fit in the magazine, and the bolt face is damn near identical to the '06. That being said, any chance the .280 AI would work in this action? How about the 7mm WSM?

Any help that can be offered would be fantastic. And please, avoid the bubba'ing comments. This particular M48 has not stock and a crummy barrel, besides I'm pretty sure someone picked up a M48 for me this Christmas.

crazysccrmd · Dec 17, 2012

I've always seen the max pressure stated at 55,000psi. A 30-06 is just shy of being too long so anything that length or smaller works.

MountainBear · Dec 17, 2012

The maximum listed pressure for the 8x57 Mauser is 57,000 PSI. Any cartridge that stay below that will do. Check SAAMI for data. Keep in mind that SAAMI specs are listed for factory ammo. Be sure not to go over pressure if you are hand loading.

Have fun! I currently have six or seven mauser projects in various states of completion...

Jamie6.5 · Dec 18, 2012

I don't think pressure is the issue.
The M48 uses an "intermediate" length action, and while the '06 round may fit in the magwell, I don't think I'd prefer one for a .280AI project, due to the cartridge length vs the action length.
The AI cartridges are prone to feeding problems on the early Mausers due to the feed ramps, and the steep shoulder angle (40*). They may need a bit of contouring and polishing work to feed easily/reliably from the mag.
When the longer bullets in 7MM are coupled with the shoulder angle and the shorter intermediate action, you may end up with a lot of bullet buried in the casing to facilitate quick, reliable feeding.

IOW, the case volume you gain with the AI cartridge may be negated by having to seat the bullet so deep, to keep a smooth, reliable feed.

For the M48, I would opt for the 7x57AI or the 7-08, or 7-08AI.
Or scrap the M48 idea and find a longer M98 action.

Just MHO, YMMV.
Good luck and keep us posted!

netcarrier · Dec 18, 2012

Hi Spaz,
I have a couple of things that may help. One we can cast the chamber to fine out what the gun was chamber for. That will tell you your pressure.
Two I have a DVD on Building the Custom Mauser Rifle from AGI.
Send me a PM if you would like to come by and check it out.
Tony Portland, Oregon Area
PS. I on 172nd SE between Sunnyside Road and Foster Road

Blitzkrieg · Dec 18, 2012

The cartridge OAL is the key, along with the fact that most magnums are out of bounds. I have a 7.62 NATO chambered Mauser and several spare FN barrels to build more when I find good receivers. 30-06 would work fine. My Mauser is 1 MOA with safari type irons

To netcarrier.. where can I get the receiver tool? I have a Mauser construction book but I know you need the receiver blank so as not to prang/warp it

netcarrier · Dec 19, 2012

Hi Blitzkrieg,
I think that Brownells will have it. 800-741-0015 URL World's Largest Supplier of Gun Parts, Gunsmith Tools & Shooting Accessories - Brownells
Tony Portland, Oregon Area

Blitzkrieg · Dec 19, 2012

netcarrier said:
Hi Blitzkrieg,
I think that Brownells will have it. 800-741-0015 URL World's Largest Supplier of Gun Parts, Gunsmith Tools & Shooting Accessories - Brownells
Tony Portland, Oregon Area

I may have had it bookmarked there but my 'puter crashed and I'm starting from scratch.. thanks

deadshot2 · Dec 21, 2012

Blitzkrieg said:
The cartridge OAL is the key, along with the fact that most magnums are out of bounds. I have a 7.62 NATO chambered Mauser and several spare FN barrels to build more when I find good receivers. 30-06 would work fine. My Mauser is 1 MOA with safari type irons

To netcarrier.. where can I get the receiver tool? I have a Mauser construction book but I know you need the receiver blank so as not to prang/warp it

You mean a pipe wrench around the front of the receiver isn't proper?

BIG_GUNNUT · Dec 21, 2012

Jamie6.5 said:
I don't think pressure is the issue.
The M48 uses an "intermediate" length action, and while the '06 round may fit in the magwell, I don't think I'd prefer one for a .280AI project, due to the cartridge length vs the action length.
The AI cartridges are prone to feeding problems on the early Mausers due to the feed ramps, and the steep shoulder angle (40*). They may need a bit of contouring and polishing work to feed easily/reliably from the mag.
When the longer bullets in 7MM are coupled with the shoulder angle and the shorter intermediate action, you may end up with a lot of bullet buried in the casing to facilitate quick, reliable feeding.

IOW, the case volume you gain with the AI cartridge may be negated by having to seat the bullet so deep, to keep a smooth, reliable feed.

For the M48, I would opt for the 7x57AI or the 7-08, or 7-08AI.
Or scrap the M48 idea and find a longer M98 action.

Just MHO, YMMV.
Good luck and keep us posted!