“I used to be one of the guys that would never run steel case in my AR. Times have changed and the Polymer cased ammo runs great in my Rock River A2 and Spikes Spartan. No hiccups or failures and it is quite accurate. A recent 10,000 round test indicated steel case causes premature throat erosion of the barrel at around 7,000 rounds, well I'm typically saving 100-150 dollars on a case so I will have plenty of $$$ to put a match barrel in when I wear these out.”