First, 3" 1911s are a crapshoot to begin with.
Second, the barrel may have a steel feed ramp or the mag can feed on the frame, then the barrel.
If you wear through the hardened part of the frame, you're screwed.
You cannot polish the feed ramp either, the hardened surface is very thin and you cannot feed hollowpoints against bare aluminum alloy.
Pluses are the weight savings, which is no benefit when you're shooting it.
I guess 3" aluminum 1911s are only meant to be carried, not shot.