I debate this myself.
Saturday I was hunting with a friend who forgot his rifle and he shot my 6mm, I shot my AR. I'd brought both for different situations. I can't say the AR gained me any yotes, but also can't say it cost me any. I killed 3 at 42, 150, and 240yds that day and all dropped on the spot. The quick follow up shots are nice but it's even nicer when the first one is placed well enough they aren't needed. If I'd have been sitting where my friend was I think I'd have pulled a double with the AR where he took a single with my bolt gun, but that's hypothetical.
I've been calling with the AR almost exclusively this year and have shot 10 calling. I'm shooting a 20" DPMS Prairie Panther or a 22" 204 Ruger AR. I can't say either has cost me a coyote, no cripples or ones that ran a lot. Shots have ranged from 19yds to 240yds, with most in the 80-150yd range. I've been shooting 55gr V max bullets at 2962fps from the 223 AR, 45gr Hornady SP bullets at 3325fps from the 204. Shot placement has been good and coyotes die fast.
I can say that the 16" AR rifles with standard (non Superformance) loads don't seem to hit as hard for me. I have chronographed some 55gr factory loads at 2750fps or less so that makes sense. I will stick to the 20" AR for calling personally.
The 22-250, 243, 6mm, on up do hit harder than the AR's, poorer shot placement results in faster kills. Yotes can only die so fast so with great shot placement I see no difference, its the marginal hits that it shows on. I do know that the 70gr or bigger varmint bullets will flat wreck a cat at high velocity. I would hate to be in a contest with a 243 loaded with 75gr V max bullets and have a bobcat step out at 80yds, I know what the end result of that is.
I'd say consider what your average and max shot range is. Look at the wind predictions for the day of the contest. Look at what your partner will be shooting, and what your strengths and weaknesses are as a team. Take what best fits the situation. I don't know that there is a wrong or right answer. The more powerful bolt gun is more likely to anchor the first yote, but this is mating season and I feel like the AR gives me a better chance at pulling a double.
I guess my final thought would be shoot the bolt gun it it's what you are used to. It took me a while to get onto the AR platform and shoot it close to as well as I can the bolt rifles. I practiced a lot to get to where I am comfortable with them. Also make sure you measure your scope height on the AR and make the necessary adjustments to your zero.
Hopefully the bugs will be worked out of the 22 Nosler by next calling season and I can build an extremely accurate, midweight, 22" upper in that caliber and not have to debate this. I'll just shoot whatever good 55-60gr bullet shoots the best at 3450fps or so and split the difference.
