The problem with Glock 357SIG chambers is not so much that they are unsupported, but that they are loose. I happily shot a pair of G32s, for years, but did not reload then. When I switched to the M&P and began reloading I discovered that that some glock once-fired cases, even when full-length resized, were so expanded at the base (below where normal resizing stops) they would not chamber in the M&Ps. I eventually got a push-thru 40S&W sizing die, which reclaims those cases for reloading.
But I would not like to see my cases repetitively streched like that at the base, and I conclude that if I were to use glocks again and intended to reload, I would use an aftermarket barrel with a tighter chamber.
Curiously, a Storm Lake barrel I bought for an M&P had a chamber so tight it would not seat half the M&P cases that wallow in a glock, and indeed was so tight a 357SIG chambering reamer would not go in without removing metal at the base. So Storm Lake would not be my aftermarket barrel choice.
All that said, my G32s gave me great service, and for factory ammo I would not hesitate to recommend the G31/32/33.
Life Member NRA, NRA Certified Pistol Instructor
Life Member New York State Rifle & Pistol Association
Last edited by k2ue; 12-09-2010 at 17:59..