I have the model with the plunger system, very reliable and much more accurate than most newer models and I've various ones. I'm talking almost cloverleaf holes(3shots) prone at a 100yards(90meters). Using a modified .457 mold which I've milled shorter to produce a 330gr flat-nosed bullet and a Crushrib sabot. Sorry, a .50cal - should have mentioned that earlier. Deadly combination