doublegunshop.com - home Forums General Discussion German & Austrian Sporting Guns @ doublegunshop.com Repairing a German "Martini"

Mike,
I'm glad that you enjoyed this project.
While I wait for the 8.15X46R reamer to arrive, I plan to finish the associated projects for this rifle which include a bushed firing pin (.070"), new main spring, spring loaded firing pin, a scope adapter for the Swiss rib, and a 8.15X46R adapter to fire the 32-20 cartridge.
I may make a .010" shim for under the case rim so that can fire form a few cases to headspace on the shoulder, as you suggest, especially if the reamer's delivery is prolonged.
Otto

Otto,
It seems that if you made cases from 30-30 brass,it would make life a lot easier for you.The nominal rim thickness for 30-30 is .063", which is about right for your rim recess(a couple thousanths to allow for tolerances).Also you could make the shoulder wherever you want it, w/o shim.I went back to the first post, and didn't find if you slugged the bore.In the first posting, you showed the proofmarks, which included 172,28. This is the bore diameter(not groove/bullet dia)as expressed in guage measurement, used before 1912( your rifle was proofed in Zella-Mehilis in Aug 1911). This equates to about 7.62mm,which is about .300".This would fit very well with the .312" bullet diameter of 32-20 (and 32 S&W long).BTW groove diameter in other 8.15x46R rifles varies, maybe up to .338",therefore the concern.If you don't already have a 32-20 reamer, you should be able to "single point" a 32 S&W long chamber in your adapter.
Mike

Mike,
Thank you again for your post. I am an a home shop machinist and appreciate the gunsmithing information that I get from my gunsmith friends and from reading forums such as this one. Many times I learn something from a seemingly unrelated project that I can apply to my own projects. If nothing else the readers will know a little more about W. Weisgerber.
The barrel will accept a ,305" pin gauge but not a .306" pin. A chamber cast showed that it indeed is still chambered for the 8.15X46R cartridge and that the grove diameter is .318".
When I finally realized that the rim depth was .065" , I made a test cartridge from 30-30 brass which filled the rim recess but still left me with .012" of headspace. I then made a .010" washer to fit over the test cartridge that gave me a rim thickness of .075" and solved the headspace problem. I'll attach a picture of the thicker case head and the adapter.
I have a 32-20 reamer as I like to reline shot out 303 and 8mm barrels for this cartridge. I considered the 32 S&W but I have neither a reamer nor cartridges for that caliber. I probably have boring bars small enough but have never tried to cut a chamber that way.
A gunsmith friend suggested that I make a washer similar to the one pictured on the test cartridge and that I solder it to the rim recess. I plan to try that approach while I await the 8.15X46R reamer, as it is simple, reversible and preserves the original parts.
Otto

Top. The Test case with washer attached and additional washers below. Bottom. A 8.15X46R adapter chambered for the 32-20 cartridge.
[img:left]http://[/img]

Otto,
Great info.I wrote an article on loading for 8.15x46R once, using examples of different rifles I had acess to.A chamber like this,with such a deep rimrecess would have added another paragraph to the article.I was resistent to the shims,thinking you meant a shim for each case.Your friends idea to shim the recess makes a lot of sense( a common way to correct excess headspace in shotguns)since only one would be required and normal shellholder could be used.The info about the barrel accepting a .305" pin gauge is interesting also.Usually owners of these rifles have the wherewithal to measure groove diameter but don't have a set of pin guages. This is another piece of info to file in the back of my mind.I guess I need to PM you,I'm about to get a little past the intent of this thread.
Mike

Mike,
A spacing washer in the rim recess seems like an elegant way to solve the headspace problem without additional changes to the original rifle.
The washer is about .005" too thick and I'll use the chambering reamer to set the final headspace, so it will be awhile before this story is complete.
Feel free to PM me if you have any questions that don't fit with this thread.
Otto
Rim recess before spacing washer
[img:left]http://[/img]

Washer soldered in place


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