Don't have the answer for you, but I'll say my Mighty Armory 308 Win. die works fine for brass that needs a .335" or more bushing. It will not give any useable neck tension on brass that uses a .333" or smaller bushing. I have a lot of the older, thin Winchester and Hornady brass that needs a 333" bushing and Winchester brass that needs a .331" bushing. Unuseable with those brass makes.
Die Works fine with Fed. GMM brass, Remington, LC 7.62 and any thicker brass. I was a bit disappointed since I have so much of the older Win. & Hornady brass that won't get neck sized enough.
My M/A 223 die seems to work fine with any brass. I've tested it with a good variety of brass with no neck tension issues.
So, do you get good seating pressure with the M/A die?