I have an update as well on my 17.5 experience and I happy to say this thing is finally shooting very good and I've had three consecutive days of stump shooting with it and great weather. From trial and error I have figured out that it does not like coated bullets, at least the ones I tried and neither does my XDM 9 or 1911's in 45 acp. Not saying they don't work, obviously they do for a lot of people but for me they do not, again at least the ones I have tried from 3 different manufacturers.
The next biggest issue and I obviously should have known better on this one but I have gotten away with it on other pistol calibers is the use of mixed brass. I was getting some really decent groups and shots going exactly where I was aiming then just some random, what the hell was that shots, when I knew I hadn't jerked the trigger. Then a few days ago I was at the bench at 25 yards and got a couple groups of three touching then one 3" out and another 5" out, then I got two consecutive groups of 4 shots within an 1 1/4" to 1 1/2" then a shot about 8" out and then on the other group about 10" out then the light came on, the brass. I switched to using the same head stamp, FC and Blazer cause that's all I got right now besides the off brand stuff, and no more random flyers and I am very happy with the way it is shooting. That is with 124 and 115 XTP, 124 Zero and 115 Evergreen LRN.
I just wanted to pass that along, hopefully it will help someone. The gun is stock with the exception of a front sight and a piece of pine wood derby putty and a Carver plug in the grip, I really like the added weight. Now hopefully I can find a 34.5 soon!!
Mike