I've been loading Xtreme 147gr plated with 3.4gr Universal (1.120" OAL) for a little less than a year. Nearly all of it's been shot through my G17 with great results. It avg's about 880fps. I was testing out some optics on my G34 today, and had two out of maybe 50 of the above load keyhole and hit the target several inches away from the group. With some quick googling, I read that keyholing can be caused by the bullet not being sufficiently stabilized due to being fired at too low a velocity. That doesn't seem a likely explanation here since the longer barrel of the G34 should be giving slightly more velocity than the 17...and I've put nearly 1000 of these through the 17 and not seen this. What else might cause this load to work well in the G17 but not in the G34? Depending on who's data you believe, I'm either .1gr over max or .1gr under max...so I could try again with 3.5gr Universal...but I'm not sure I want to. Other options for increasing the FPS would be WSF (which I don't have), or WST (which I have used). 3.5gr WST at 1.145" gave about the same FPS as the above 3.4gr Universal load. I've read of people going as far as 4gr WST with 147gr JHP. Suggestions?