So I have been reading alot but didnt see a post reference having a tungston (sp?) guide rod. I shoot fatory ammo, well because its free for me. Speer Lawman 180 grain. I just ordered a new tungston guide rod for my G35 and a set of springs in 13, 15, and 17. So which one do you guys think I should use. Seems from what I have read 15 sounds like a winner. Please let me know what ya think.