If it's all stainless (guts and tube), and uses machined cones rather than pressed freeze plugs...would that be GTG?

Full-Auto rating is a Manufacture use Warranty.

Full auto rated cans use materials that retain their strength and erosion properties at dull red-hot temps (1100-1200 F)*.
Inconel, steelite etc are what is used. These are expensive and a real pain to machine.

IMHO the best you can do is overbuild the can wall & baffle thickness and use something like 17-4 SS

Do you really want to beat up your MG barrel by doing multiple mag dumps?



*Standard 300 series SS will have <25% of their RT yield strength at these temperatures, think about the implications of that.

According to what a fairly respected commercial manufacturer on another forum told me... the ability is determined by not only the capability of the materials to maintain strength and erosion resistance under high heat, but also (and just as important) the material's abilities to conduct the heat away from the center of the baffles and other hot spots to the exterior where the heat can be shed.

That's why you see some full auto rated stuff with 6061 aluminum baffles. They conduct and shed heat incredibly well.