Take a look at the Speer GoldDot Personal Protection loads for reference.
.44 Special standard load is a 200 grain .429" JHP at 875 fps with a BC of .145 for 340 ft.lbs. at the muzzle
.45 ACP standard load is a 230 grain .452" JHP at 890 fps with a BC of .143 for 404 ft.lbs. at the muzzle.
The .44 is tested from a 6" barrel; the .45 from a 5".
The .45 in the short barrel (4") uses the same bullet at 820 fps for 343.
I've shot the .44 from a 3" barrel and clocked it that right at 820 fps, and the .45 from a 3" barrel and found it at just under 800.
If those are near ballistic twins, I'm not sure what would be. I will take, and do take, either and feel quite secure in their capabilities.
I take it that you don't give the added diameter any merit.
