Brass vs. Steel Cased Ammo – An Epic Torture Test

[Hunter07]

A very long, very detailed, interesting article. Pics, videos and graphs are very well displayed in the article.

Here’s what we did:

We acquired four identical Bushmaster AR-15 rifles. We chose the Bushmaster MOE Series AR-15 because it’s a widely available, affordable, and mass-market. We didn’t want something too cheap and of lower quality or something too expensive and of high quality since our goal is to help the most number of people.

We acquired 10,000 rounds each of the following ammunition (new production):

Federal 55gr – Brass-Cased – Copper Jacket
Wolf 55gr FMJ – Steel-Cased with Polymer Coating – Bi-Metal Jacket (steel and copper)
Tula 55gr FMJ – Steel-Cased with Polymer Coating – Bi-Metal Jacket (steel and copper)
Brown Bear 55gr FMJ – Steel-Cased with Lacquer Coating – Bi-Metal Jacket (steel and copper)

We paired each ammunition type with a specific Bushmaster AR-15 and then fired all 10,000 rounds of it through that particular carbine (except for Tula; more on that below). We systematically observed and tested various things, including (more details below):

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

The rifles were cleaned according to a preset schedule and temperatures were monitored and kept within acceptable limits (more below)

We sectioned the barrels and otherwise made unique observations after the test was complete

If you’re interested in any of the following, you’ll find observations, data, and further details below:

http://www.luckygunner.com/labs/bras...-ammo/#erosion

[buzgun]

wow....lots of great information there...thanks for posting it.

[Pogo]

Yes. That is a very informative article.