Originally Posted by
RevolverRob
If it's "grabby" then it hasn't been fitted well enough, yet.
It should unlock and lock smoothly. When it does, then what should happen under a controlled feed principle is that as the round moves up the feed ramp, the barrel starts tilting back upwards from it's lowest position, it will catch the nose of the round and support it, while the case rim slides under the extractor and everything chambers. A mistimed barrel will thus not support the round properly during feed and cause the nose to jam right into the barrel feed ramp.
It's "close" because it runs ball, which is slippery enough on the nose to slide past the hiccup caused by the not properly fitted barrel. I bet if you looked close, there is a spot on the feed ramp with some extra copper on it from the bullets hitting.
You can "cheat" your way into functioning, by raising the magazine up higher and making it a "straighter" shot into the chamber, or by 'polishing' or throating the ramp to eliminate the speed bump, but it's all unnecessary if the barrel is fit right. FWIW, Wilson mags work, by short-circuiting the controlled-feed and delivering the round higher and straighter into the chamber. It's one reason they work so well across even problematic guns, because lots of 1911 barrels aren't timed right, but are "close enough" that you can get them to work.