Fired 200 rounds of WWB today. I had only 1 malfunction which I think was due to a defective cartridge, not the gun. The slide would not close on the cartridge, but I discarded the cartridge and had no problems the rest of the day.
I did notice that a few times after inserting a loaded magazine, the trigger pull felt very gritty on the next pull. However, this seemed to clear up after a few magazines. I think the gun just needed to "break in". Anyone else have something like this happen?