it doesn't look like anyone as truly answered your question. i use a cz 527 in .223. it has a 1:12 twist with a simple Burris 3x9 fullfield 2 ballistic plex. the chamber on a CZ is basically a wilde chamber so it shoots both well. i was using 50 and 55 grain Hornady fmj to save the hides on coyotes. i went to the 53 grain vmax because it shoots the speed of the 50 gr but has the energy of the 55 at 100 and it has a better b.c. than all of the bullets up to and including the 62 grain vmax. I've shot coyotes out to 450 yards with all the loads consistently. I've taken it out to 500 on prairie dogs. the rifle shoots well even up to the 75 grain hollow points. i wouldn't be afraid to take your choice of rifle out to 450 with the 55, 53 grain bullets. don't let the theoretical nay sayers who don't take their rifles to the field discourage you. take it to the range. take plenty of ammo to shoot 5 shot groups at 100,200.300,455,500,600. make yourself a chart of the drops at each range and the group size. when the group is to big for a clean kill that's your limit. I'm not usually going to say why i qualify to give you advice but I am a gunsmith for over 40 years experience with an emphasis on ballistics. reloading since 1978 and calling and shooting coyotes since the early 70's. you won't know how it is going to perform unless you take it to the range. aim small miss small.