Some years back we were testing Winchester .45ACP Black Talon into water.
We fired rounds from a 5" Colt Government and the rounds opened fully.
We fired rounds from a 4.25" Colt Commander and the rounds only opened about half as much.
We fired rounds froms a 3.5" Colt Officer's ACP and the rounds were barely deformed.
The short barrels had a great effect on Black Talon .45ACP.
Proud NRA Benefactor Member