Accurate .223 for long distance in 20" with 1/7 twist?

General Firearms Reloading & Ammunition
1

What factory ammo should I be looking at for this purpose?

I will be shooting out to distances of around 600 yards at times, and want something more accurate than my M-855 and M-193.

2

These below are highly accurate and at a good price. I’ve shot the 69 and 75 grainer out to 1000 yards with accuracy in my 1/9 twist 26" Savage 12FVSS. What rifle platform do you have?

http://www.snipercentral.com/shop/index.php?cPath=94_102_110

3

Anything with a 77 Gr. Sierra Matchking HP

www.black-hills.com

Federal Cartridge GM223M3 Fed Gold MDL 223Rem 77gr BTHP

4

I put 40 rounds of the BH 77gr BTHP out of the SR-15 yesterday. What a difference. Much tighter groups. Ammotogo had them at around the same price as the ones at sniper central (albeit the re-man Blue Box) but they shot fantastic.

5

I am using a 20" AR platform with this caliber.