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

Otto,
Off center primer strikes in my brother's Martini 8.15x46R were caused by too thick rims(cases also made from 30-30 cases, with rim dia.reduced, but not thinned).Since the breechblock seemed to close, we didn't see a problem at first.We tracked the off center strikes to the thicker rims not allowing the block to rise completly.If you plan to try pistol primers anyway,I suggest you thin a couple rims from the rear( pistol primers are a little thinner anyway)and check both the firing pin firing a pistol primer, and striking it in the center.I am sure the offcenter strikes make it harder to fire the primers,especially since the original .254" primer wouldn't be as critical for this. If it was easy, it wouldn't be nearly as much fun and anybody could do it.
Mike

Gunwolf and Mike
Thank you for your help. I've decided to modify the original action and at the suggestion of a local gunsmith (DK) will add an extension to the lever to begin striker retraction before the breach block begins to rotate.
It may be awhile but I'll revisit this post when the modification is complete to share the results.
Otto

Otto,
Be sure to take photos,I'm interested in the project. It would be good to see photos of the process.
Mike

To facilitate the action modifications needed to allow firing pin retraction before the breach block begins to rotate, I made a testing fixture.
The first photo shows the action modifications. An extension has been added to the lever and the lower leg of the striker hammer has been extended.
The action is shown fully cocked.
[img:left]http://[/img]

The picture below shows the initial phase of cocking. The striker is retracted before the breach block begins to rotate.
A return spring has been added to the firing pin to give prompt firing pin retraction as soon as the hammer pressure is relieved.

[img:left]http://[/img]

The breach block begins to rotate but is not yet in contact with the striker.

[img:left]http://[/img]

The breach block has rotated enough to contact the striker and complete the cocking.


[img:left]http://[/img]

Otto,
Great,and it didn't take much time at all.Have you shot it yet? Good show.
Mike

Mike,
It may be awhile before I get to shoot it. I need to correct the excessive headspace and it will probably be six to eight weeks before I receive the 8.15X46R reamer.
Otto

Otto,
Interesting that you have a 8.15x46R reamer comming. Are you renting(if so, who from)or having one made?.Is the problem with the rim recess,or has it been rechambered?
Mike

Mike,
It looks as if the rim recess for the 8.15X46R was deepened to .065". In addition, the breach block easily closes with a .012" feeler gauge between the barrel and breach block. I wonder if both changes were made during the prior attempted restoration in an attempt to free the firing pin.
The barrel threads are 24TPI, so one turn of the barrel should be enough to correct the headspace. Then I'll have to deepen the chamber, recut the rim, recut the extractor slots and correct the forend hanger.
I've ordered a reamer from PTG as I have another 8.15X46R project to do after this one.
I'm sure getting my moneys worth from this rifle.
Otto

Otto,
I would think your speculation about the source of the excess headspace is as good as anyone elses.Since you have another 8.15x45R project(and I'm selfishly glad to locate a reamer)I won't recommend taking excess headspace out of the cases by fireforming and setting the sizing die to just "kiss" the shoulder, nor by moving the case rims forward like we did with the 45-70 to make Mauser "A"base cases.I don't know if .012 is too much, but you do need some space between the breechblock and barrel, otherwise you may have trouble with seating some cases.You want the breechblock to bear against the casehead rather than the barrel(I didn't think this up out of the blue, I made a similar mistake before).I too am having fun with this project, and I didn't have to pay anything.
Mike