I had a few malfunctions this week and I wonder if it may be the KKM barrel needing to "break in". It seems pretty tight but not bad enough IMO to have it fitted. On one occasion it failed to feed, once the slide held open even though the mag was not empty (looked like it was going to be a stovepipe though) and once it did not hold the slide open on the empty magazine. Any ideas? All were with the same mag since I only brought one. I was going to take the pistol in to Robar to get the slide NP3+ coated but I am holding off in case it needs warranty work. I tried assembling with the factory parts last night and it is WAY "sloppier". your thoughts? Magazine issue? Ammo (they were relatively hot)? Barrel? recoil spring still stiff (tungsten)? I am still unfamiliar with the 10mm and the larger frame Glocks.