For the test, 10,000 rounds each of Federal, Brown Bear, Wolf, and Tula ammunition in caliber .223 Remington were used. Each brand of ammunition used a 55 grain full metal jacketed bullet with a lead core. The Federal 55gr .223 ammunition featured a solid copper jacket and a brass case, while the other three brands used a bimetal (steel and copper) jacket and a steel case. The Brown Bear ammo’s steel case was coated in a green “lacquer,” while the Tula and Wolf cases were coated with a gray polymer.
Four brand new and identical Bushmaster MOE carbines, Bushmaster model BCWA3F MOE, were used. Each was produced in Ilion, New York at the same facility where Remington rifles are made.
[From LuckyGunner Labs website]
This article shares so much data on Steel vs. Brass cased. It is a long but very good read if you have ever been in, heard or thought about the steel vs. brass debate.
The GEARS crew still uses steel for the sheer fact that it is cheaper to do reviews with. When we head out to the range we are likely to shoot 1000+ rounds on a given day and we have yet to set up a reloader (fingers crossed for Christmas).
One thing you should be aware of when buying a new rifle is that some manufacturers do carry a warning on the packaging saying that use of steel cased ammo will void the warranty.