Well, I've got my hands on a M48 Mauser parts gun and I want to rechamber with something with more oomph that will still work through the mid-length action. I think an 8 mm-06 AI will be too long.



It seems like an 8 x 57 AI is what I'm after but I can't find dimensions on Clymer's web site.



Can anyone forsee problems using 7 x 57 AI dimensions for the body and shoulder and 8 x 57 for the neck and pilot?



Well I see that the stock 8 x 57 base to shoulder length is greater than the 7 x 57 AI - so that's an obvious problem. Looks like its back to the drawing board - literally. I'll have to dust-off geometry to calculate AI base to shoulder length given less tapered body and 40 * shoulder angle. Any suggestions on how to approach this?



TIA!

DobleTroble,

Well, I can help you with this one as I have done it. Dave Kiff @ PTG did the reamer for me following the original guidelines that P O Ackley stated. I used a surplus Yugo mdl 24 that had an excellent barrel. You MUST remove the barrel and do the necessary set-back prior to chambering with the Improved reamer. Since the barrel is not cartridge marked it is not necessary to set it back 1 full turn. (I set mine back 0.025 and rechambered .004 short as per Ackley recommendation). I still have the stock to fit & finish so I can not report any accuracy/velocity readings. I have only test-fired with factory Remington ammo and all went well, a very nice clean chamber.



Good luck with your particular firearm but I would suggest you do the regular rechamber.



Ol' John



PS- Oops! Beg your pardon..left off some of the requested info....Length from base to 40* shoulder..1.8612"---base to juncture of shoulder and neck....1.923"...diameter at 40* shoulder...0.455"....... These measurements from the reamer spec sheet provided by Dave Kiff @ Pacific Tool & Gauge, 598 Avenue C, White City, Oregon 97503...541-826-5808

A few years back, there was an article in the Handloader's Digest on one of these 8X57 Improved cartridges. I believe the rifle was built on a Ruger No. 1 action. It seemed to be an excellent design, quite powerful, at least equal to a standard 8mm/'06.

Doble Troble:



Do a search on the Gunsmithing forum ( newer than 1 year).



Look for "Hotrodding", (must use quotation marks) user name - wildcat junkie.



There are several alternatives listed for the M48/VZ500 actions.



The 8X57 A.I. Model I did on "Quickload" did not show a signifigant improvement.

Thanks for the info guys. Damn you're good!



WJ: Excellent analysis of 8mm rechambering options. Do you have Base-to-shoulder and shoulder diameter for the 8mm-Steyr AI?



HondoJohn: Thanks very much for the 8 x 57 AI specs. I've figured-out how to make my own reamers and will give this one a try as my next project. From WJ's analysis it probably won't make much field difference, but should be easier on brass and those 40* shoulders sure look cool