Test Findings: For a multitude of reasons, the test crew determined that Federal brass-cased ammo was “healthier” than steel-cased ammo. The brass-cased ammo shot more accurately, had far fewer malufunctions, and produced less barrel wear. The USA-made brass-cased ammo also showed more consistent velocities. CLICK HERE to READ FULL TEST.

Watch the video below for a summary of results:

Torture Test Procedure
Four types of .223 Rem ammo were tested: Federal brass-cased 55gr FMJBT; Wolf steel-cased (polymer coating) 55gr FMJ; Tula steel-cased (polymer coating) 55gr Bi-Metal Jacket; Brown Bear steel-cased (lacquer coating) 55gr Bi-Metal Jacket. Each ammo type was paired with a specific Bushmaster AR-15. Tests were performed at various round-count stages:

• At the start: record accuracy, velocity, chamber and gas port pressures, make chamber cast
• After 2,000 rounds: record accuracy, velocity
• After 4,000 rounds: record accuracy, velocity
• After 5,000 rounds: record throat erosion, make chamber cast
• After 6,000 rounds: record accuracy, velocity
• After 8,000 rounds: record accuracy, velocity
• After 10,000 rounds: record accuracy, velocity, chamber and gas port pressures, throat erosion, extractor wear, chamber cast, barrel wear, make chamber cast.

During testing, rifles were cleaned according to a preset schedule and temperatures were monitored. After testing, LuckyGunner sectioned the barrels and made careful inspections.

Click the links below for specific data, test results, and conclusions:

• Which ammunition was most reliable?
• Which ammunition was the dirtiest?
• Which performed better, lacquer or polymer coating?
• Which ammunition maintained the highest degree of accuracy throughout the test?
• Which ammunition maintained the most consistent velocity throughout the test?
• Which ammunition caused the most throat, barrel, and extractor erosion/wear?
• What effect did the powder burn rates have on bolt cycling?
• How did the pressure at the gas port vary by ammunition type?
• How did the pressure at the chamber vary by ammunition type?
• Which is cheaper to use, after considering all the costs?

During the testing process, all malfunctions of each rifle-ammo combination were logged. The brass-cased Federal ammo was the clear winner: Federal: 10,000 rounds, 0 malfunctions. Brown Bear: 10,000 rounds, 9 malfunctions (5 stuck cases, 1 mag-related failure to feed, 3 failures to cycle.) Wolf: 10,000 rounds, 15 malfunctions (stuck cases) Tula: DNF (6,000 rounds in alternate carbine, 3 malfunctions)

Barrel Wear and Throat Erosion
Some of the barrels didn’t make it to 10,000 rounds: “The steel cased/bimetal jacketed ammunition caused accelerated wear to the inside of their respective bores. While the barrel of the Federal carbine had plenty of life left, even after 10,000 rounds … the Wolf and Brown Bear barrels … were completely shot out by 6,000 rounds. At the end of the test, the chrome lining of the Wolf and Brown Bear barrels was almost gone from the throat forward, and the barrels had effectively become smoothbores[.] A throat erosion gauge could be dropped into the bore from the muzzle end with absolutely no resistance.”