Re: Loaded Ammo for .338 Win Mag ?
This varies so much from rifle to rifle that I did not put accuracy results into the table. The Sako preferred the Winchester Supremes with the 200 gr. Ballistic Tips, the M-70 shot its best groups with - REMINGTON el-cheapos (225 grain). This was the average of three 3-shot groups, not a really big test but both rifle shot right at 1.0" with those cartridges. Fact is many of the groups shot when I tested all that ammo averaged between two and three inches - but that is how it was, not how I wanted it to be.
I have much better accuracy with handloads, have had amazing accuracy with 225 Hornady and Speer bullets and also 225 Swift A-Frames if you like to spend money. The .338 is a fairly punishing bruiser on the bench so I only shoot 3-shot groups and always wear a PAST recoil shield - these are fairly light rifles and they beat me up.
A while back I tested a Ruger .338 that my buddy bedded into a very nice HS Precision stock and it shot a couple of 0.75" 3-shot groups with Winchester 200 gr. PowerPoints, again one of the cheapest factory loads out there.
Although it is neat to test a variety of ammo, you must determine what bullet weight is most appropriate for the size of the critter you are hunting. Use the 250's for big, heavy-boned stuff like moose and the 200's for deer. The Federal Premiums loaded with 210 Nosler Partitions are my favourite all-around hunting load - even if they shoot two or three inch groups that is still going to raise hell with a moose or bear within a couple of hundred yards. Not the accuracy that this forum is focused on, but it is good enough for 90% of our hunting under most conditions.
Shoot that rifle as much as you can so that you get really good with it, and it will kill anything you point it at.