Re: 7STW & Sierra Gamekings?
back in the 70's I shot the 175 gameking long range out of a 7mm-300 wby which is the same thing basically. My best loads were with H-870 I think. The newer powders you have should work great. The 175 gameking was the second highest BC hunting bullet on the market those days with the 250 grain 338 bullet the highest. It has a stronger antimony lead core than most other gamekings so it holds together fairly well unlike most gamekings. Now I use the 162 Amax with a higher BC and better velocity. For deer size game it will work.
Predictions are difficult, especially when they involve the future