Quote:
What Effect Do Coatings Have On Steel Cased Ammo Performance?
A common belief is that the lacquer coating of certain steel cased ammunition will “melt” in the chamber of a hot rifle and cause subsequent rounds to fail to extract. At one point, we might have believed that.
But in this test, we saw three times as many failures to extract with the polymer coated Wolf brand ammo (15 extraction failures) than with the lacquer coated Brown Bear ammo (5 extraction failures). Although we fired the polymer coated Tula ammunition in different rifles, the rate of extraction failures in those rifles was lower than that of Wolf.
There will be a very small number of stuck cases experienced when shooting steel cased ammunition, but we didn’t see a correlation between lacquer coatings and stuck cases.
If anything would make that lacquer coating “melt,” it would be the treatment these rifles received during the test. We shot them until they were too hot to hold – hot enough that a chambered round would cook off in ten to fifteen seconds. We also tried leaving rounds chambered before temperatures reached that point. None of this harsh treatment caused extraction problems.
We found no evidence to back up the claim that lacquer coatings melt in the chamber and cause extraction failures.
Quote:
Why Did The Barrels Wear The Way They Did?
Certainly one of the most visually striking parts of this article is the inclusion of post-test barrel cutaways. We cut the barrels axially with an angle grinder and then longitudinally by the wire EDM process. This lets us see exactly how the barrels wore throughout the test. There were significant differences.
The first answer to this question is, “Because we shot them until they got hot, and then we kept shooting them.”
The rate of fire definitely contributed to rapid barrel wear. Still, other factors played a major role.