First, I love mine. It has functioned fine until I tried the sellier and bellot FMJ. This stuff is hot, and the slide won't strip a round off the top? If I pull the slide back and let it fly no problem it goes into battery. My question gang is this-what do you think is going on? Is it simply recoiling too hard. Will a heavier spring fix this? It is the same OAL as the Winc.FMJ which funtions great? I give up.