Have you tried the newest nitro 3.5 inch shell? Think its 2 7/16 of hevi's. I know guys are getting over 300 with them and thats with the bigger shot mixed in. I'm pretty happy with the way my gun is shooting with cheap lead ammo but if I was going to go with heavier than lead I'd skip the factory stuff and go right to nitros. I don't see a big enough of an improvment with hevi-13 or xtended range over what I'm shooting now.
