A while back, an MOA customer contacted me with a “Is this normal?” type question regarding 5.45x39mm leaving pits on AR500 steel. I shoot quite a bit of 5.45x39mm myself, but all of it is milsurp 7N6 steel core ammo, which should not be shot at steel targets. The customer in question had been shooting a variety of 5.45, none of which was steel core. To answer the “Is this normal?” question, he kindly returned one of his targets to me and included a box of each type of ammo he was using for testing.
MOA started cutting a QA/QC target out of each sheet of AR500 used in making targets, to act as a test bed a couple months ago. It also provides a great excuse to have more targets for the MOA range. The Customer Target is from an older, pre QA/QC batch. AR steel is through hardened, not surface hardened. The hardness should be consistent throughout the sheet. However, as this is the real world, and the testing is destructive. Each batch is tested, not each sheet, and not each section of sheet. Pitting on factory steel is not uncommon, and softer and harder spots can exist. Additionally, the method used to cut the steel can affect hardness. MOA Targets uses a 4,000 watt CNC laser to do the cutting. It makes nice, smooth cuts, and has a heat affect zone (HAZ) typically less than 1/8” on 3/8” AR500. Torch cutting will have a far larger HAZ, as will plasma. Water jet has no HAZ, but is much, much slower.
For control, three known standards (known to me, anyhow) were used as well as the various 5.45 loadings. Controls were 7.62x51mm DAG milsurp with a 150 gr lead core nickle washed steel jacket projectile, 5.45x39mm milsurp 7N6 with a 52 gr steel core copper jacketed projectile, and 5.56x45mm XM193 with a 55 gr lead core copper jacketed projectile.
Photos from the testing can be found here.
The QA/QC target from a recent 1/2” AR500 batch was used for the test, as a standard to test the Customer Target performance against.
All testing was conducted at 100 yards on MOA’s private range.
Test ammunition, provided by the customer, included Wolf 60 gr, 69 gr, and 55 gr loadings, and Silver Bear 60 gr, all lead core with a copper washed steel jacket. Additionally, Hornedy 60 gr VMAX was provided, which is lead core with a copper jacket and a polymer ballistic tip.
At the conclusion of the test, it was evident that both the QA/QC and the Customer Target performed well within expected spec, but that the QA/QC target (from a more recent batch) appeared to be harder.
And that’s how we do science at MOA Targets.
PS: For the curious, the customer will be getting his target and ammo shipped back to him, along with some “Thanks for helping out with science” steel from MOA.