Tracer, I'm also working with a couple of other rifles that I want to work up accurate loads for; a 1993 700 Classic in .222 and a 700 SPS Varmint in .223. The .222 may be my biggest challenge as it has a 1:14 twist according to what I'm able to find. Logically, it should do best with light bullets but when I shot it the other day with 50 grain Speer softpoints, it didn't please me at all. Of 15 3-shot groups fired at 104 yards, only one was in the .5" range and most exceeded 1".... some by quite a bit. My scope is a Weaver Grand Slam and i was shooting from a benchrest at 20X. Five different powders were used. I'll work my way up through 52/53, 55 and 60 grain bullets to see which perform best.
Yesterday I shot 8 3-shot groups using four different powders in the .223 700 SPS Varmint rifle. I used only 60 grain Hornady softpoints and only one group exceeded 1" by a small amount. My best three groups were .383", .318" and .310". The best was shot using 24.5 grains of IMR-4320 powder. My scope is a Tasco 10~40X50 World Class Plus set at 32X. The reticle is a FCH with a 1/8 dot. I want to try more groups when I can get a box of better 60 or 62 grain bullets.
The 6mm Remington 700 VLS will get worked in too but I want to gather as much information as possible before I build any more loads. I'm encouraged that your best groups came with IMR-4320. While I haven't used it in the 6mm yet, I will. My best results to date have been with IMR-4350 and IMR-4831,... both slower than the 4320.