My long-time carry pistol is my 1.0 M&P 40c, converted to .357 SIG with a Storm Lake barrel. It has been exceedingly reliable for over 16,000 rounds, and has not had a single failure in the last 4,500 rounds. I usually shoot Lawman ammo with it, but I recently bought some Sellier & Bellot .357 SIG 124g HP ammo because that's all I could find. It had no ballistic info on the box, so I went to the S&B website and found these numbers: muzzle velocity: 1476 fps; muzzle energy: 597 ft/lbs. Yikes!
Naturally, I had to check it out in my 40c, and what followed was really ugly. Over two range sessions I fired 30 rounds of S&B and had at least 7 instances of trigger failure to reset (I stopped counting), as well as 3 failures to fire. The failures to fire were due to hard primers, because my striker left a very deep dent in those primers. I consider that to be an S&B problem.
What concerned me more was the trigger failure to reset. That's a 40c problem. My guess as to the cause was that the slide was moving so fast, that somehow the trigger was not being reset. Is that a plausible explanation? After the first range session, I replaced my old recoil spring assembly with a new one, which was noticeably stiffer. I hoped that it might slow down the slide to reduce the no-reset problem. Obviously, it didn't work, so now I know not to use the S&Bs in my 40c.
I subsequently shot 40 rounds of Lawman and 10 rounds of Gold Dot (both 125g and 1350 fps) with zero problems, so I know my 40c is still working OK if it can handle those. I'll leave the super-hot .357 SIG ammo to my SIG P229. The S&Bs work just fine in it, so I do have a gun to shoot them from.
Any informed comments on why the hot S&Bs caused my failure to reset problem are welcome.
Naturally, I had to check it out in my 40c, and what followed was really ugly. Over two range sessions I fired 30 rounds of S&B and had at least 7 instances of trigger failure to reset (I stopped counting), as well as 3 failures to fire. The failures to fire were due to hard primers, because my striker left a very deep dent in those primers. I consider that to be an S&B problem.
What concerned me more was the trigger failure to reset. That's a 40c problem. My guess as to the cause was that the slide was moving so fast, that somehow the trigger was not being reset. Is that a plausible explanation? After the first range session, I replaced my old recoil spring assembly with a new one, which was noticeably stiffer. I hoped that it might slow down the slide to reduce the no-reset problem. Obviously, it didn't work, so now I know not to use the S&Bs in my 40c.
I subsequently shot 40 rounds of Lawman and 10 rounds of Gold Dot (both 125g and 1350 fps) with zero problems, so I know my 40c is still working OK if it can handle those. I'll leave the super-hot .357 SIG ammo to my SIG P229. The S&Bs work just fine in it, so I do have a gun to shoot them from.
Any informed comments on why the hot S&Bs caused my failure to reset problem are welcome.
