The issue here, it seems to me, is really how low one should go in terms of PEAK pressure where vintage gun X is concerned. I've never been a real low pressure Nazi. I know some guys liked their PB loads at 5,000 psi or so . . . but I was never one of them. At some point, someone here stated that if you have a gun that can't handle peak pressure somewhere around 8,000 psi (might even have been you, Miller), then it's probably not a good idea to shoot it. I'm pretty much in the same camp. Given what we've learned about vintage loads going way back, they weren't lower pressure than that. Never mind the fact that if you live where I live (serious cold country) and shoot when it's below freezing, you'll often get pretty poor performance from very low pressure loads. I've heard very weak sounding Winchester low noise/low recoil loads in cold weather (far weaker than when it's 70 or so). Reloading manuals used to give us hints along those lines. Like "not a good cold weather load".
But given the fact that pressure only goes one way (down!) after its peak, it seems to me you'd need a pretty darned thin spot down close to the muzzle if you were going to blow the barrel there. Has anyone ever heard of a gun that's blown out near the muzzle as a result of a very low pressure load? I can't recall anything here. And that's an unusual location for a catastrophic barrel failure anyhow, unless maybe there's a muzzle obstruction.
