.45 ACP APN is the usual culprit to jam on me
Yes, using a suppressor. Yes, I let it cool off.
No, did not switch ammo.
Ok, I did some digging and found only little to the Jam mechanics that we did not already talk about considering that it has been around for ages. The new "Wave" of failures might be due to the Weapon temperature and damage models giving it some more variables that might have made it more random. But this type of things usually gets dialed in over the cause of development (dont forget, we are still talking about a not finished game).
One thing that might also be a factor could be the difficulty that you are playing on.
There could also be a small chance per bullet in a Mag that there might be a feeding error, meaning that the .45 ammo (One, if not The ammo type with the highest capacity Mags) is more prone to failure or you just got unlucky.
You should be able to narrow down your cause of failure by checking your gun parts in the gun-konfig-menu once they have jammed (it should show you something related to the part that caused it) or by looking at the "Un-Jam" animations (there are multiple that might be played depending on the cause of the jam).
This might not be a solution but it should help you to find a way to work around the problem.