I have run a little over 150 rounds of cheap practice ammo though my new razorback flawlessly. The other day I was going camping in grizzly country and picked up a box of 220 grain +p and loaded a magazine up. The first time I racked the slide it jammed up before the round was fully chambered. It took some considerable force to open the chamber again. I tried with a few more rounds (chambering no firing) and got similar results. A few rounds chambered and a few didn't. I unloaded the rest and tried cycling a whole magazine of target ammo and it was flawless again. Any ideas?