Personally, I would not want to shoot a bullet that heavy in a 223 due to a really poor trajectory at ranges of 300 yards and shorter.
A 50 and 55g Bullet will get the job done without having tricky trajectory.
I have killed a bunch of yotes with a 223 using the Sierra 50g Spt, 55g Winchester, 55g Sierra lead tip blitz, and the 55g Sierra BTHP.
You never have to worry about the bullet detonating on the surface with any of these bullets, they will punch holes through both shoulders.
The 55g Winchester is a very soft bullet, loaded with 26.5g of Win 760 is one of the most fur friendly loads in the 223 that I have ever found, and has the omph to take out a lion or javelina also. I also killed two does with the same load, dropped in their tracks. The cheap 55g Win is one whale of a yote bullet.
Today, there is kinda a politically correct thought train that you need to shoot a plastic tip bullet, don't get caught up in it. It is amazing at how a 50g Sierra Sp kills yotes, also.
N-133 with the 50's and N135 powders will maximize the speed with extreme accuracy out of the 223's.
I shoot a load with the 50's at 3500 fps and the 55's at 3400 fps with 1/2" groups at 200 yards.
If you are shooting an AR, then I would go with the Sierra 55g BTHP...unreal accurate bullet and a little tougher for the faster twist that you probably have in the barrel.
Of course those of us that have shot a bit with the 223 at at fair distances(I've never fired a match with the 223 past 1000 yards yet) know that drop is not where its at.. its wind resistance. Anyone can click a rangefinder and adjust, but the wind drift is the guess area, hence the reason that past 200, I'd never choose a light bullet as suggested, My 75s don't drop much, zero'd at 200 you'd hold top of the back at 300, not rocket science..... and I don't recall having any rifles zero'd at less than 100 in many years, in fact my 100 yard bench is rotted away currently.
But to each their own. Some want to see bang flops and red mist and you usually don't get that with heavy bullets. That being said I have yet to miss any coyote this side of 350 or so with my 223s and 75 grain bullets.....
