txinvestigator wrote:Charles L. Cotton wrote:Stephen:
I I have around 5,000 rds of 170 gr. cast 40 S&W that I can't shoot through any of my Glocks.
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Please forgive my ignorance. Why not?
Apparently, the polygonal rifling in the Glocks tends to shave the alloy from the bullet and fills the grooves rather quickly, even to the point of reducing bore size and driving pressures up. When all of this came out a few years ago I didn't buy it, primarily because I've shot a lot of cast bullets in Glocks. (They were hard cast to be sure, but there were cast bullets nonetheless.)
But there have been too many report of Glock KB's with cast bullets and I've heard reports and opinions from very reputable people who believe there is a significantly increased risk. A Glock rep. at the NRA Annual Meeting confirmed the problem, but since all manufactures say "don't use cast bullets" or reloads, I tend to take that with a grain of salt.
Whether it's absolutely proven or not, I'm not sure, but I won't continue to push my luck. I've switched to all cast bullets anyway, so I'd really be hot if I had a KB on the last 5k cast rounds!
Chas.