I don't use 4350 and never had used it, except in 243. I would go to Varget. Varget in 308 is better than factory. It took me just 3 loads before I got the right one and its consistent. I don't believe you have a brass problem, but I would do a full length resize everytime, and make sure of your case length, don't worry about moving the bullet out to touch rifling (higher pressures) until you get the problem resolved. Also if you have a cannurl on the bullet , don't crimp the neck too tight, also if bullet does not have canurle like Sierra , do not try and crimp those at all. Hope this helps ; these are problems I went through over the years. You just got to take it one step at a time. Make sure you have a quality mic to measure with too. (not those plastic dial ones)