I have a Ruger 77 MKII in .223 with 12" twist. Bought the rifle new in '91 and it's been shot a great deal, mostly with 50 gr. and 55 gr. varmint bullets. I didn't try the 65 GK in it, but the 63 Sierra did very well with 100 yard, 5-shot groups of well under an inch using H4895. For comparison, the 60 Partition grouped over 2" and the Nosler 64 Bonded did around an inch and a half.
