saddlertime

Just to clear up something that may cause some confusion, the "undercut head" is not the head diameter that is smaller. The term "undercut" pertains to the part under the head near the threads. The bottom part of the head is shorter so that the screw can have more threads. This is typically done for small length flat head machine screws because the length of a flat head machine screw is from tip to tail so to speak where as a button head screw length is only the threaded portion. For example this link shows a #8-32x3/8" Non-undercut screw: http://www.mcmaster.com/#cadinlnord/96640a123/=n6h4ng This link shows a #8-32x1/4" undercut screw: http://www.mcmaster.com/#cadinlnord/96640a122/=n6h5pl You can see that the head diameter is still 0.312", but it is only 0.070" thick rather than 0.100" like the standard screw. I just wanted to make sure that it is clear that if the snap ID is too small for the OD of the screw head, an undercut head won't help. If the screw head isn't seating down deep enough into the socket, then the undercut head may be your solution

Just using the photos you posted and measuring my computer screen, I get that the Colt is a little longer (I measure 1/8") in the distance from the front of the trigger guard to the end of the slide. I measure roughly 1-1/4" from the front of the trigger guard to the end of the slide on the Colt and 1-1/8" on the Springfield, and I measure basically 3-1/2" overall length, so those photos on my screen must be pretty close to actual size. I don't know if that helps any or not, but there you have it.

I believe this explains the material under the pants.

I just have to throw my vote in for my favorite brand of gun even though it is far less common than all the ones you have listed, and if fact the fact that no one I could find makes a holster for it is why I started making holsters. I am in love with FN Herstal FNX-40. This isn't about guns, so I won't go into that, but I just wanted to throw my vote in even though it wasn't one of the choices.