I am torn between a 20'' or 16'' barrel for a Bushy that I am interested in buying. This will be my first AR since leaving the army. I will not be shooting over 100 yards. Is there any major difference between the 20 and 16'' barrels? I want the M4 but want to be competitive with my friends at the 100 yard range. What kind of grouping can I expect at that range with the M4? I know it will depend on ammo, but I'm looking for an estimate.
The question can be posed two ways.
The longest barrel you can deal with
or the shortest barrel that delivers the ballistics you want with acceptable blast, flash and sight radius.
Forget all that. Just go with cool factor. Three inch barrel.