The hole should point away from you; directly at the bad guy.
When the little lever is pulled, there will be a load noise.
If you had the hole pointed in the right direction; there will be another hole in the bad guy.
If he is still moving, repeat the pulling of the little lever until he isn’t.
If the load noise does NOT occur after pulling the little lever, the safety may be on or the gun may not have any little brass cylinders in it.
I pray I never get to that point.
That is priceless!