Well, I went to the range today and fired my Colt XSE Commander. I was having problems with Colt Checkmate magazine, so I switched out the mag spring with a Wilson Combat spring. I started out with Winchester Ranger 230 grain and immediately had FTF. So I switched to a Wilson mag and continued to have FTF's. The slide also wasn't locking back occasionally either. I switched to ball ammo (CCIBlazer brass) and had another FTF with the Colt magazine. I switched back to the Wilson magazine and the gun functioned. There was only one more FTF with a partial ball/Ranger filled mag. So...I switched over to Federal Hydrashock and the gun worked perfectly. I ran out of Hydrashock and switched to my last box of Ranger and had more FTF malfunctions. The funny thing is, I tested the Ranger ammo out when I first got the gun and it worked fine. The recoil spring has over 1500 rounds/cycles on it. I just ordered new springs from Wolff. The only saving grace was the accuracy of the gun, and the fact that I believe this is just an ammo and magazine problem. Ughh..