I am looking for any extra information I can get in regards to the Hornady GMX 70gr load for 5.56mm, I know Black Hills makes a load and Hornady of course. I know it has a great B.C. and sectional density. It is marketed as barrier blind, 95% copper/5% zinc composition. Does anyone have experience with this particular load or know if this meets DocGKR's criteria? It looks like the 55gr GMX load made his list, I have had excellent luck with the 300 B.O. loaded GMX and am wondering if the accuracy and expansion lives up to the hype on paper. The purpose for the GMX for me would be a general defense load for two legged, pest control (pigs about 250lbs max). The pro's as I see it is being able to produce a practice load that runs really close to factory loading,(HDY 68gr AMP), good factory load performance across my range of needs, lastly rounds I can use in both an SBR or my 14.5". Right now I can't really see any negative aspects thus far and am wondering if I am just ignorant of something/blind.