Not an uncommon problem with the 34's. Mine did the same thing no matter what ammo was used. I'd suggest a call to S&W.
The best defense is a good offense, and I'm really offensive.
SFC, U.S. Army, Retired 1971 - 1992
S&W Club #92, Snubbie club #92, The 21 Club #92, Glock 23, S&W 28-2, Ruger 10/22, Beretta 92FS