Jon,
I have only owned two 338's and they were both Rugers. One had a synthetic, the other a brown laminate stock. Both were SS and had sights as well. GREAT rifles both of them. In factory form they were under 1 moa guns easily with 250gr Barnes X bullets, all I ever shot through them. Most of the time they shot .5 -.8 moa but I never messed with the load because it was always under moa and I never shot over 3-400 yards back then. Mine both liked hot loads and always grouped well there, I wish I could say that about a few other guns I own but usually groups double in size at max loads on them. Some of them are ridiculously low in velocity before they group that well.
We were out a week or so ago and a buddy of mine had his older Ruger 338wm with him. We shot it with some Federal 225 highshocks or something off the shelf like that. It was under .7 moa with two different types of bullets, both factory stuff. To top it off, we were both shooting the groups as well!
Savage makes a hard gun to beat, but all the 338wm in a Ruger I've seen shoot, will always shoot sub moa groups, factory too.
I remember once we went out shooting filled water ballons, the little round ones the size of a baseball at best. We were at 200 yards and leaning on the truck doing this too. We had stuck the ends you blow through on tree limbs, hanging them all over in the tree like a Christmas tree.
We were using factory fed 225gr partitions, cheap stuff wally world had on sale in the isles at 20 bucks a box. We never did shoot any groups with them bullets but we hit water balloons one after the other after the other for about a 90% success rate! I remember looking at the gun thinking, I can't believe how accurate it is with these bullets!! Never found them on sale again and started loading the barnes bullets after this. I found that the "gun" was just accurate!
If you can get the Federal High Energy brass, it was giving me alot higher velocities than the regular fed stuff.