I have a 5.5 inch 22a-1, and love it.
I bought a 22a with a cracked frame, and with the shorter barrel for cheap.
Yes they do interchange..
I make 2 predictions:
ON THE DATE WHEN US TROOPS ARE ISSUED AN Energy Pulse Weapon,
1. The US Soldier will have on his person a version of the Colt 1911.
2. He will be aiming the NEW Weapon at someone carrying an AK.