G19, only a few months old. Recently introduced a few mods and now having a feed problem. The spent casing ejects fine but the slide will jam on the new round. It is not a "stove pipe" which tends to apply to spent casings. The round is down in the slide assembly....like it simply did not hit the ramp correctly.. It requires turning the pistol over and pulling the slide back to dump the round out. I usually drop the mag first and then clear the weapon. This is not a good option in a defensive situation. Mods: Added a S/S guide rod, a 15lb ISMI recoil spring, and an extended slide release. I also purchased several non-Glock magazines recently. I shot 180 rds y'day and had 5-6 misfeeds. One of which was a total failure to load a round. Slide moved, I pulled trigger and "click"...no bullet. (I experienced similar failure about two week ago when I shot. I did not think to check which mag (factory or non-factory) was in the gun when it misfed but will do so next time. The gun was clean at the time. i shoot Winchester 155gr FMJ for target rounds. Just looking for some ideas and if anyone has experienced similar.