JR - I have two different questions. I have a Lone Wolf 9mm conversion barrel for my G 22 and it works great. Will this barrel also work in my G 17? Are there differences in stock Glock barrels that could impact accuracy? I have two G 17 Gen 4s. One is less than 4 months old but I have put about 3,000 rounds through it. The other is 1 month old and only has about 200 rounds through it. I notice when sighting the older G 17 from the bench that it really didn't shoot consistently tight groups. Two days ago I put the newer G 17 barrel in the older G 17 and it improved dramatically -- shooting extremely tight groups (from the bench and on sandbags just like the other G 17). I am practicing for a match and shooting Atlanta Arms 147Gr JHP Match ammo on these tests (880 FPS). As I do these tests - I am set up through a Chrony and the FPS on all measured shot are less than + or - 3% of the spec 880 FPS. I am testing at 30', 45'. 60' and 75' with the same group patterns.