In spite of all the advances in the shooting world, tech, gear, manufacturing, I suspect there is a LOT we don't know about what actually happens between the time the primer ignites and the bullet leaves the crown. We have all seen quotes from some of our best barrelmakers in the world, something on the order of, "there is no telling whether a given barrel will shoot or not, until you shoot it" or something along those lines. In my opinion, the famous "Houston Warehouse" tests wasn't so much about verifying what we know as telling us there is a lot we don't know...yet. Also, in my opinion, there is a physical/mathematical/engineering reason why a certain barrel seems to not like a certain bullet...we just don't have the money, motivation or determination to research it in depth. My 7x57 BRNO may be the rifle you refer to above...it has always been a problem child, my first guess is it has some built in stresses in the barrel itself that cause strange harmonic anomalies. I have tried to shoot at least 4 rather elaborate ladder tests with it and it still defies a rational diagnosis. But it's mine, and I'm going to live with it.
