You need a slick 75-82.
The 77 SMK is not slick.
The 80 SMK is a good starting point, as is the 82 Berger. They are both easy to get along with, don't have real finicky-bitch personalities, and jump okay/shoot better that way. The 80 JLK is one pointy SOB, but it does not have a relaxed personality to say the least.
Problem is, 80's have to be pushed pretty hard. Granted, a bolt gun can do that, but primer pockets are still what they are.
Higher performance can come from some of the VLD/Hybrid desings and the AMAX, ELD, etc. The trouble is always that they are tougher to get to shoot sometimes.
At 800+, without the ability to run 90's, you really don't have a choice but to look up the HIGHEST B.C. figure you can get in an 80, and get it to shoot. If it won't, then you move down the line until you find one that will hold under 2" vertical at 300 meters and keep windage squared away.
I'm sorry, but if you wanted a 1,000 yard .223, you needed to make a different barrel choice. Longer & tighter.
-Nate