How does the colt m911 differ from the m911a1 and the m911a2?

Answer 1

The Colt .45 pistol is an M1911, not an m911. The changes from an M1911 to an M1911A1 were:

1. the relief cuts behind the trigger

2. the short trigger

3. the arched main spring housing

4. the longer tang on the grip safety

There is not m1911A2.