I havent used the SST but have usedthe Barnes 225gr MRX with good results in the 338 Lapua. I am tired of looking at some Lost River Ballistic Technologies 200 gr J36'as sitting on my shelf and am fixing to load some up and see what they will do. Been trying to get a hard BC on them with little success, closest I can figure is that they are in the .550 range. Should be able to get 3200 or so out of them.