Depends on the FMJ, but it was at least as good as American Eagle or White Box through my Colt. I only shot out to 15 yards this weekend, but was getting 2-4" in the head box of an IDPA target pretty easily at that range running some drills. I didn't do any slow-fire accuracy testing of it since it's marketed more towards dynamic shooting, but it certainly wouldn't have been worse than 2" at 15 yards if I had slowed down.
Comparatively, Win3Gun seemed to be shooting a little tighter than the FMJ I had on hand, which was Federal AE 230 grain this trip, for what it's worth. When I get my hands on some of the 9mm in the next couple of months, I'll do some accuracy testing as well. I honestly didn't think about it that much. The gun also had the factory Colt barrel in it, so this isn't a bullseye gun by any stretch. Hope that helps.