I only have one handgun, a S&W 4006, so that would be my loudest. Took me a while to figure that one out
. It's definitely not as loud as any magnum revolver, but it makes a pretty decent bang when it goes off. I find that at my local range my 4006 (.40 S&W 4'' barrel) seems to be louder than the 9mm's and .45's people bring.