I have a Winchester built [1916] P14 that I have done a bit of work to, and it is amazingly accurate for it's age and original purpose. I have yet to shoot anything out of it that actually shoots "badly", with most of the loads I have tried going into 1¼-1½" However, a couple of loads stand out. One is the 150 Hornady [.312] with Vihtavuori N540. It shoots into less than 1" regularly, with my best 3 shot group at 100 being .54" The other is Steve Regdwell's Mk9 200 grain Semi-Spitzer [.313", same as my groove diameter] It shoots into around ¾" regularly, loaded with a powder that was Made by Nobel of Scotland, and marketed by Higginson as 47N. The 180 Sierra Spitzer will shoot about 1¼" all day long, and is probably the best long range bullet for the 303. I use Reloder 15 for it. Most of my loads are in the 308 Winchester class, since there is no need to baby a P14 Action, and the chamber in this one is fairly tight as military specs go, so it is easy on brass, unlike many SMLE's. I carry it as a "truck" gun, and am willing to take shots to 350 Yards with it. My goal is to harvest a nice spring blacky with it this year. Besides being a bit heavy, I really like this rifle! Regards, Eagleye.