Robert,

Thank you very much for the information you have posted. It certainly helped a lot to clarify the matter.

In fact, I have never personally given much attention to proofing. The only occasion in which I had any experience in this area in the past was one visit a few years ago to the Imbel plant (the same factory that produces our Army FAL's and Springfield Armoury's 1911 .45ACP pistols). During that visit, I could see the proofing of a few FALs and pistols. This is routinely done at the factories, and they use special cartridges especifically loaded for that purpose by Magtech/CBC. Unfortunatelly, this is not a service they provide to the general public, and Magtech/CBC does not produce ammo (regular or proof) for the .444.

Even so, I am more confident now that I can come up with a good proof load that will give me the desired sense of the safety of my project gun. I tend to aggree with some of you in that proofing is something best left to especiallized proof houses. But I would feel even more idiot if I decided to build a gun and shoot it without any form of testing!!!

Fred