1. The 5.15" LW barrel makes more of a velocity difference than I thought it would. With 4 different identical loads, velocities are almost 100FPS higher. 2. This LW 5.15" barrel is also the most-accurate I've had in any of my Glocks. For instance, today's 20 5-shot groups averaged 3/10-inch smaller than the essentially same loads shot over the weekend thru the original barrel. 3. After a little preliminary velocity measuring Tuesday nite, the groups I shot today were strings with lower charges of Longshot and A7 and 4 loads of A9 creeping up to what I thought I wanted. Turns out 3 loads--1 with A7 and 2 with A9--of the 9 loads I shot had too-HIGH velocity for my desires for a 155g. PD load. Some may, but I don't need a PD load generating 10' velocites over 1375FPS, but it's sure a nice problem to have. :embarassed: 4. Based on ONE batch of 18 groups from 9 different loads, so far the loads with A9 are generating the smallest groups, but that's only by a tenth of an inch at 10 yards. I sure am liking this.