David, using a short barreled .45 will make follow up shots harder to control than a full size, but if that's what you've got, go for it! The last match I RO'd, we had a guy show up with his carry piece (an officer size 1911 in .45) and he got 2nd place overall. He is a regular shooter and wins a lot of our matches. One of the guys bet him that he wouldn't be in the top 3 if he used his carry gun and he took that bet.
It is more the Indian than the arrow