RP,
I have found Bore Tech C4 the be the most effective. I have been using it for a few years now. I've tried some others (some good, some not) but keep coming back to Bore Tech products.
C
Re: Data for ALL Cals Ackley Imp
260AI
26" Bartlein bbl
Lapua Brass
CCI BR2
45.3c H4350
142gr SMK .010 off lands
3005fps, 420'+- ASL, 73 degrees
.25 MOA or better if I do my part