Glock 19 and Glock 34. Both just got new threaded barrels. Barrels are drop in, but fit nicely. I'm omitting the name of the barrel company for now because I'm going to email them in the morning and see if they have suggestions... Ammo is 147gr RN from Freedom Munitions and the ammo cycles fine without the can. With the can, the round fires, but the slide does not even attempt to cycle or eject the round. On both guns, the barrel goes into battery with a new round just fine. Both barrels had about 100 rds through them before I tried the can. Can was screwed on tight. I was not limp-wristing the guns. Silencer is an AAC TiRant 45 with the proper size piston and the Neilson device installed. The spring seems to work just fine and the can was recently cleaned. The can works just fine on 9mm and .45 1911s so I'm thinking I can rule that out. Everything so far points to the barrels, or ammo. Both guns properly lubed/clean. Thoughts???