I have a Mini-14 (580) with a 18.5 inch barrel 1:9 twist in a .223 cal. I have read that the heaviest weight is "about" 69 grains that my rifle will stabilize. I have been reading my "Hornady Handbook of Reloading" and it has a section on ".223 Remington Sevice Rifle Data" and it states with a barrel of "20 inches, 1:9 twist (ie AR-15) you can load 68 gr, 75 gr and 80 gr.
The section on ".223 Remington" states with a barrel of "26 inches, 1:12 twist, I know is for a bolt type rifle (ie Winchester 700) you can load 40 gr through 60 gr. I have found the best loads for my rifle is 50-55 gr.

The question I poise is: Will a 75 grain A-Max stabilize and shoot well from my 1:9 twist rifle?

It will be used for mostly target, but maybe a deer or two.

I'm always looking for a good load and I know Hornady know more that I and what I have read.

Targetslayer