Greetings, rhkary!
Coincidentally, I also have acquired a No. 1 in 338 Win Mag. I have just completed an initial run of tests on loads for two bullets; the 200gr Combined Technology Ballistic Silvertip, and the 215gr Sierra SpBt; using IMR 4350 posder.
I have two very promising loads I am going to explore further:
With the 200gr Ballistic Silvertip, 72.5 gr of Imr 4350 gave me an average velocity of 3,059 fps and a 3 shot group of 1 in.
With the 215gr Sierra SpBt, 71.0 gr of IMR 4350 gave an average velocity of 2,956 fps and a 4 shot group of 1.3 in, a 3 shot group of 1 in; with shots 1 and 2 overlapping by half.
I have also bought a box of Hornady 230gr ELD-X bullets I am intrigued by, but so far have not been able to find any published loads for them. Not even in Hornady's load app!
If anyone has worked with these, please share!
I'm really looking forward to the postings on this thread; I hope it garners interest!