Originally Posted by SCmasterblaster
My carry load in my G17 is a 115gr bullet doing 1400 FPS. The bullet has a low sectional density and ballistic coefficient, so I wonder about how it will do trying to penetrate through several inches of heavy clothing. I am thinking of changing over to a 147gr JHP in the upcoming cold VT winter. Do I underestimate the fast 115gr JHP bullet?
I think that you are.
Heavy clothing lacks the tensile strength to stop a bullet. It may clog the expansion cavity of a jacketed hollow point bullet, but the JHP will then behave as a FMJ producing even more penetration than if it hadn't been clogged.
This PDF contains a clothing penetration model that may be of interest to you-
Check it out.