Yeah, that gun on DH has always been a fickle beast because it has such a short barrel the ball can bounce out. Adjusting the wireworm that drops the ball into the gun one way or the other helped on mine so I have almost zero drop outs now.

Also make sure the gun comes to rest at a good angle which may or may not be adjustable with the switches underneath.

I never choose load gun anymore anyway. I always go ramp shot or occasionally take the bullets.