ginge,
I cannot answer your question about Hollenbeck records, but I think some others here can. I take it, from your text, that your gun will be Proof Tested, not just "shot" with 2 3/4" shells. This is not a bad thing. Is it actually marked for 2 3/4" shells? If not, the standard shell length(at the time)was 2 5/8". This is easy to confuse with 2 3/4". It might be helpful to have your German gunsmith friend to verify the chamber length, and lengthen it if not actually 70mm.Doing this before the proof testing, might save a lot of "tooth gnashing". Also, I believe you can have the .25-25 barrel nitro proofed, at the same time. I believe you will need to provide cases, bullets and duty load. I think a nitro proof of this barrel would be beneficial thing. The K&S Einstecklauf has a good name, and would be a very useful thing to have. A major advantage over the older ones( in addition to much wider range of calibers)is the ability to adjust the point of impact( of bullet) at the muzzle. I believe it would be helpful if you could address, in detail, how you went about having this done, as well as some idea of the cost. By this, I mean in whatever publication you submit the project in.
Mike
