Luckygunner.com finally (data like this takes a long time to compile and analyze) posted the results from their comprehensive 40,000 round .223 ammunition test.
The full story in the Brass Cased Ammo vs. Steel Cased Ammo can be seen here and if you’re thinking about skipping it let me just say that the results may surprise you. If you’re one who’s always said, “I never shoot steel cased through my AR because it will ruin it,” or “The lacquer from steel cased ammo builds up in the chamber and feed ramps and makes my AR-15′s action stick” you will most definitely be surprised by the test.
Not only are old and inconclusive myths debunked (the unreliable myth, the “foreign ammo is dirtier myth”), but the effects of wear and tear on the barrels and gas ports are much more conclusive than I had imagined they could be.
It’s a long read, but something I think you won’t regret spending a few extra minutes diving into. The brass vs. steel cased .223 findings posted by Luckygunner here could very well save you both a lot of time, heartache, and especially money.