The question of brass vs. steel ammunition has spawned a seemingly never-ending debate from new and seasoned shooters alike. Our team at Lucky Gunner Labs took 4 brand-new AR-15 carbines and a total of 40,000 rounds of 55 grain FMJ ammunition from Federal, Wolf, Tula, and Brown Bear out to the Arizona desert for an epic brass vs. steel ammo torture test to try and scientifically settle this debate once and for all. Scroll down for a written summary of our test, click here for our 2-minute video summary, or go read the full test results at Lucky Gunner Labs by clicking here. Our Test Tools: 4 new Bushmaster MOE series AR-15 carbines. 40,000 rounds of factory-loaded 55 grain FMJ ammo from each of the following 4 manufacturers (10k rounds p/manufacturer): Federal: Federal 55gr FMJ Brass-Cased Copper Jacket Wolf: Wolf 55gr FMJ Steel-Cased with Polymer Coating Bi-Metal Jacket (steel and copper) Tula: Tula 55gr FMJ Steel-Cased with Polymer Coating Bi-Metal Jacket (steel and copper) Brown Bear: Brown Bear 55gr FMJ Steel-Cased with Lacquer Coating Bi-Metal Jacket (steel and copper) Our Test Methodology (Full Summary): We paired each ammunition type with a specific Bushmaster AR-15 and then fired all 10,000 rounds of it through that particular carbine. We systematically observed and tested various things, including: At the start: accuracy, velocity, chamber and gas port pressures, chamber cast After 2,000 rounds: accuracy, velocity After 4,000 rounds: accuracy, velocity After 5,000 rounds: throat erosion, chamber cast After 6,000 rounds: accuracy, velocity After 8,000 rounds: accuracy, velocity After 10,000 rounds: accuracy, velocity, chamber and gas port pressures, throat erosion, extractor wear, chamber cast, barrel wear We logged every malfunction of every rifle-ammo combination. We cleaned each rifle according to a preset schedule and temperatures were monitored and kept within acceptable limits. We sectioned the barrels and otherwise made unique observations after the test was complete. Our Test Results For Reliability (Full Summary): Federal: 10,000 rounds, 0 malfunctions. Brown Bear: 10,000 rounds, 9 malfunctions (5 stuck cases, 1 magazine-related failure to feed, 3 failures to fully cycle). Wolf: 10,000 rounds, 15 malfunctions (stuck cases). Tula: DNF (6,000 rounds in alternate carbine, 3 malfunctions). Our Test Results For Cost (Full Summary): Federal's brass rounds performed the best but certain brands of steel-cased ammo are most cost-effective, even after factoring in the cost of replacement barrels. Click here to read more. Full Report Summary (including an overview video, pictures, methodology, and full findings): Click Here To View And most importantly, next time you're engaged in this age-old "brass vs. steel" debate, use the 40,000 rounds of ammo we put down-range in our test to back up your position! http://www.luckygunner.com/labs/brass-vs-steel-cased-ammo/ Wanna kill these ads? We can help!