I had good luck with both H4895 and AA2015 pushing the 200grn Hdy ILs and 200NBTs. I've been tinkering with the 160TTSX and I4198 lately. The 160s shoot descent(around MOA), but I'm only getting around 2700 thus far with I4198 and I'm not sure about them expansion wise at extended(200+)ranges.
My 338 fed is a T3 with a ridiculously short mag length. With the 200s 2015 was my best combo for the short mag length, but H4895 was the winner when changing to a longer mag and LA bolt stop. May have to give R15 a try as well.
