Take some snap caps or fired cartridges and put some tape over them so you can see if the firing pins are striking the primer. Then close the gun pull the triggers, check for penetration. Retape then close the gun and reopen it without firing. See if any pin protruded enough to mark the tape. I've had a couple 20s and with one used one I found some one had dry fired the gun, the pins will "neck" since they are free floating and some times will stick and can fire the gun upon closing. Easily repaired but very dangerous. Other then that just a standard check out. The guns are very strong. I managed to drop mine off the truck by leaving on top of the dog box. Other then a dent or two in the stock the gun was unfazed. They are pretty bullet proof. Also nice to carry and to shoot.
