Shazbat:
I think the main thing you would lose is sight radius. Within 25 yards, I don't think you'd see much difference if you put them in a ransom rest.
You'll have to be more specific on what type of target shooting you want to do, as different types of shooting require different guns. For IDPA, you have to go 4". For pin shooting, I can't see where you'd want more than 5". For silhouette shooting, 6".
For hunting, you can get more velocity out of a 6", so that might be important.
If you're just talking about plinking, I'd take the 4" -- better balanced.
M1911
[Edited by M1911 on 03-22-2001 at 02:49 PM]