I had one heck of a time getting RL17 and few people are using the 7WSM. I am guessing not many have tried it.
I finally found 2 jugs of RL17 and bought them both. It works wonders with the 06 for sure. I am guessing the charges in the 7WSM might be reduced compared to some slower powders like RL22 and R25 so a improvement in velocity may not be as significant.