I have a Colt Officers ACP Series 80 and have run into an interesting problem. Whenever I am shooting ball ammo the gun is 100%. When I switch to ANY brand of JHP the last round "stovepipes". Not a real stovepipe, but the unfired round gets lodged vertically in the chamber. I have tried multiple magazines and run into the same problem. As I said, FMJ work fine. I have replaced the stock recoil spring with an EGW full length guide rod with flat ISMI spring at 22#. It did same thing before the recoil spring upgrade, so can anyone help me figure out what the issue may be. I am thinking I need heavier mag springs?? Thanks!