If he had an SKS. That is NO sniper rifle. He was using it as a battle rifle in an extremely target rich environment. (With all due respect for the brave officers who were killed or injured)
Quick magazine change would make a difference.
Some SKS have/had a propensity to “slam fire.” Go full-auto. This caused more than one shooter to be ejected from a range and also, more than one getting a visit from BATF. I believe it was the early Russian models??