I've been running bulk pack Winchester Xpert HV from Walmart in my 617. Today I managed to get just a tick under 3 inches at 50 yards using a cheap reflex, a sandbag, and bench resting it. While I would like to have seen a 2 inch group, to be honest I don't think that ammo was the problem. One thing I found was that the image of the reticle in the sight shifted some when I moved my head, which is something at a real quality reflex wouldn't exhibit. I've also found that it's a real challenge to hit a target well at a distance where you can't even see detail in the target. Finally, as I have found out, getting a consistent release at these distances is not as easy as it sounds.

As for the Xpert HV, IMO it's probably good for 1.5 inches or better at 50 yards. I didn't see any signs of verticle stringing so the power level is consistent. About the only thing I would complain about is that it is a rather smoky ammo.