Hello Pards   One of my two Colts (in 45 Colt) consistently shoots about 4" low at 10 yards. Though I bought it used, the sight hadn't been filed. The other Colt is "on the money" (it had it's sights already filed). The one that shoots low is about .015" higher that the one that's in the "X". I've chrono'd the loads with each gun and they are pretty much identical.   I plan to file ever so slowly at the range with my set loads. File a stroke or two, put it on a rest, test fire, repeat as n