They can absorb a lot of lead before disintegrating. There are ricochets, but they're not much of a problem. I thought someone was playing around and had poked me until I realized it was a ricochet. The pins are bowling center discards. Plus a whole lot of lead and gunpowder.
Stock guns are just the way they come out of the box with the exception of target sights.
A pin gun, usually a .45 semiautomatic, has a compensator added to the barrel to increase the weight and keep muzzle rise at a minimum. Space guns have a laser scope added. And they treat the guns accordingly. Club members also must be National Rifle Association members. Visitors are welcome, but are monitored closely.