the way i understand it is that blockland's physics operate by cartoon physics standards superimposed over simplified real physics
in other words your magnum fires bullets physically larger then it is but simultaneously you suffer recoil appropriate to it's size and the enemy suffers knockback according to it's size and the amount of force transferred
and then the bullet disappears.
You can sustain your elevation in the air temporarily by shooting a shotgun at the ground.
You can take a sniper shot to the face and live.
You can survive being blasted into the air by an explosion.
You can stand near an explosion and not suffer from shrapnel.
HOWEVER, Bushido, the guns don't turn you black in the face when someone shoots you point blank. Looney Tunes will teach you all you need to know about guns.