I found my notes on load development for my 338Fed. Rifle is REM 600 with a 21" barrel. All brass is resized RP 308WIN with CCI LR primers. It was shot at 100yds on a cool 50degF day with less than 5kt wind (at my back) in GA.
IMR4895/200gr Hornady SP (All loads less than 1") 46.0gr: 2491, 2493, 2501 46.5gr: 2528, 2508, 2521 47.0gr: 2553, 2546, 2555 THE WINNER
I also tried the 185gr TSX with WIN748 and IMR4895. The results are not worth posting. Very inconsistant MVs and groups. I was torn between the 210NP/WIN748 load or the 200SP/IMR4895 load. In the end I went with the latter since I use IMR4895 in my 7mm-08 and 223. Commonality of components helps especially with the prices lately. I hope this helps...