08-20-2014, 10:18 PM
Steel alloy type will be a huge variable with it. Soft 416R Stainless vs. CMV barrel steel are quite different when you look at the Data Sheets for them.
When I looked at the original chambering of the AR15, .222 Remington at 50,000psi Maximum Average Pressure, and thick wall hoop stress calculators, some very clean, rounded numbers popped out with a very large FoS far wider than 5.56 NATO. It's one of the main reasons why there is such a stringent alloy callout for M16 and M4 barrels.
When I looked at the original chambering of the AR15, .222 Remington at 50,000psi Maximum Average Pressure, and thick wall hoop stress calculators, some very clean, rounded numbers popped out with a very large FoS far wider than 5.56 NATO. It's one of the main reasons why there is such a stringent alloy callout for M16 and M4 barrels.