JD and Top, I had one of them buggers for a few years not too long ago. I found a couple of little secrets to them. One is finding brass for the 250 savage is about like finding a needle in a needle stack. Second trick, it is better to use a case from a 6.5 creedmore. Using a 22-250 case is okay but you end up a few thousandths short and you have to anneal the case head after fire forming. The 6.5 creed you have to trim so you have the right length and no need for annealing. Since you aren't ending up short you wont have to adjust load because of case capacity issues. I's also use a Hornady sizer instead of the RCBS because of the smoother ball sizer.

Keith was dead on correct about the bullet size vs twist issue. Those early 250savs didn't shoot anything over 85, sometimes 90 grain worth a tinkers damn. Some did get lucky with 90 grain Sierras when they had them, not 100% sure they have them still but I'm pretty sure Nosler has 90 grain Ballistic tips in .257.