I have used 250 & 300 SMKs with several 338s. I shot some of the gen 1 300 grain burgers with good results as long as I did not push them too fast. That problem seems to fixed with the gen 2s. I just have not gotten around to ordering any yet. One of the guys on this site has been having great results with Cutting Edge bullets, both the 225s and 252s. I have some of both but have not had a chance to load any yet.