Quote:
Originally Posted by SeamasterSig
Snowman, combustion gases are moving much faster than the bullet possibly can. It's not so difficult to imagine that they can easily get past the bullet before the bearing surface contacts the tighter chamber throat. Also, don't forget that throat size can vary slightly even within the same cylinder despite S&W's best intentions. Add to that the fact that the jacketed 125s that are the culprit IMO are nominally .357 but can vary slightly in practice. Another variable that is difficult to account for is the fact that overall lengths vary from one bullet design to the next for any given weight, so you can't really go by weight alone even if weight is a good general indicator of size. The real question is precisely how far any given bullet (of a specific weight/shape) has to move for combustion gases to get past it and how far it has to travel before sealing off those gases. Factor in the burn rate of the powder and it gets complicated. Your guess is as good as anyone's. So by all means, follow your conscience, your own observations, and the advice of people you trust.
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Hello, SeamasterSig. Thanks for the response. And before I forget, I respect you for continuing to use magnums in your 66 in spite of the steady drumbeat of voices who counsel against it. That has always seemed to be an extreme view, to me.
The view re the problem with 125s which I posted here was one I read on this forum a few years ago. It was expounded by one of the more knowledgeable fellows here -maybe one of the gunsmiths(I'm sorry that I can't remember who it was.). Though others before and after have echoed its general principle; i.e. "slow-burning powders and lightweight bullets", he was the only one I've seen who posted graphs of pressure curves according to burn rate, and articulated the theory in greater detail than others have. And so I am getting the view from someone else here.
There is a question or two in my mind re the view you've explained that perhaps you can address if and when you're able. I'm understanding the basic principle: With a shorter bullet, more of the burning gas gets around the bullet before it seals in the chamber throat than is the case with a longer bullet. But here is what I don't understand, and I'll do my best to accurately express it: How does the burning gas which escapes the chamber throat into the barrel AHEAD of the shorter bullet put more wear on the gun than the
pressurized burning gas which fills the barrel BEHIND the bullet(regardless of the bullet's length/weight)? Do you see what I mean? The gas which escapes the chamber ahead of the bullet also escapes the pressure created by having to push the bullet through chamber and gun, does it not? If so, then there is little pressure to force it out the B/C gap, which, as I understand things, is what accelerates the wear and tear on the K-frame forcing cone; i.e. an increased amount of gas at increased pressures shooting out the gap.
Anyway, don't feel that I'm demanding an answer, or am being contentious; neither of those is true. I'm just a mechanically-inclined fellow with an inquisitive mind.
Best regards,
Andy