I have a M336cs 30/30 Marlin (with micro-groove rifling) that I'm trying to get better accuracy out of with hard cast gc'd bullets. Would you fellows recomend the .310 or .311 sizing die? I already have the .309". I also shoot some in my 30-06 but already get fairly good accuracy with the .309". Also, there could be a time when I wanted to lube a bullet without sizing it if heat-treated. Thanks BM

Bill

You'll have to slug your [well-oiled] bbl. first to determine whether you need to size to .310" or .311". As for lubing CB's without sizing, you can use a larger sizing die if they're gas checked or swirl them around in liquid alox & mineral spirits as per Lee's instructions if they're not. ...Maven

I size my bullets to .310" for all my 30 caliber rifles. For the Marlin, I size to .310", then heat treat to harden. Gas check was applied at time of sizing. After heat treating, I lube with a .311" die.Groups run from 1.5 to 2.5" at 100 yards depending on the bullet design I'm shooting.
Paul B.