Ultimately, you have to perform your own quality control. And along with this you must know what's above your pay grade, gun-repair-wise. I've learned painfully, and at great expense, that there's a point at which you turn the firearm over to a pro. Last year, I needed to adjust the rear sight on a SIG-Sauer 1911, which was fitted so tightly in its dovetail groove that all hell would not budge it, nor would a Brownell's sight mover. So I took the pistol to Gus Norcross at Angus Arms in Wiscasset, ME who specializes in 1911s and military rifles. Gus is not only a highly accomplished gunsmith, but has a Husky that wanders into the shop and yodels for extended periods of time. Gus showed the rear sight what was what in a matter of minutes.