And if there isn’t a more effective weapon in action nearby, things have gone horribly, horribly awry … unless it’s the start of a trench raid, or there are Maori or Gurkha troops nearby. Those guys have a significant reputation for hand-to-hand fighting at arms’ length or less, which itself is topic for a whole new thread.
As to the mod1911A1: I have held one of those pistols, and found it as easy as a Glock or Beretta as far as weight. Given that, while for ammo availability I’d go 9mm, I do know the .45 is a very damned effective pistol.
Regards, Uyraell.