The gun should be angled upwards more so that it looks like MC is hitting people by bringing down his forearm, kinda like a backhand, but with the bottom of a closed fist. The speed and damage should remain the same. The way it was in SPv1 didn't look like it had any power behind the blow, since it was just bringing down the bottom side of the silencer onto someone's head with a short weird swinging motion. I didn't really care though since I barely used the SMG in SPv1, since the silencer turned me off. I will use the un-silenced one though...