Re: 600 Yards with a 1911?
Hitting a full size silhouette at 100 yards is good but not really outstanding; I have done it pretty regularly shooting DA, two hand standing with a 3" Model 36 and standard .38 Special ammo. Also, I have put every shot with that Model 28 from a rest in a group about 4" at that distance.
But the trouble is that MOA really isn't very consistent at the longer ranges, as there are just too many variables. A pistol that will shoot 2" at 25 yards won't necessarily shoot 8" at 100 yards.
When Colt was "hyping" the AR-15 and the .223 (it wasn't the 5.56 yet), they did an ad showing a GI helmet with a bullet hole in it, saying that their wonderful new rifle would penetrate a helmet at 1000 yards. When some of us questioned that, not only on power grounds, but on the fact that no one could even see a helmet at that distance, let alone hit it, Colt admitted that "we did some computer simulation" and that they actually shot the helmet at 50 feet. So much for advertising.