Here's a handy dandy little comparison of diverse bottom feeding pistols. Check the ones you'd like to see, smallest one comes to the front and each succeeding larger pistol will be placed in the background, or vice versa. Start large and overlay the smaller ones on top to get an idea of comparative size. So far they are not doing a top view, just the side view on size so one doesn't get an idea of thickness.

https://nivlam.github.io/