I guess that I had better get over to my friendly supplier of "odd stuff' and clean out the last of his Berdan goodies.

Has anyone ever thought of using a hydraulic press and a a couple of "custom" punches, to solve this problem?

1. Flatten the anvil and deepen the Berdan pocket slightly.

2. Use a "ring" punch around the outside of the pocket , to reduce the diameter to hold large-rifle Boxer primers.

3. Punch or drill out a new central flash-hole.

GP-11, being almost exclusively fitted with lead-based primers, should not crack and fail like the common, 1/4", mercuric-primed .303 brass.

I am just a little dubious about the retention of a very thin collar, especially when it comes time to go for the second reload.

Keep us posted, please.