January 04, 2011
My favorite powder for the .30-06 is H4831, but Richard Folsland, Norma's representative here in the U.S., told me that Norma's URP powder happens to perform magic with bullets of the 180-grain persuasion. I decided I'd better prove him out, as I've long been a fan of 180-grain bullets in the '06--a result of growing up in elk country where a deer load that wasn't also an elk load was generally considered a waste of time. So I selected a 180-grain hunting bullet I trust for its inherent accuracy, dug out some of the empty brass that I'd fired through the Kimber 84L, and dedicated a Saturday to discovering whether URP could match my old favorite.
I neck-sized the brass, intending to pull out every accuracy-enhancing trick I had in an attempt to beat the accuracy results I'd gotten with factory ammo. After uniforming primer pockets and chamfering, deburring, and brushing the inside of the case necks, I primed 40 cases with CCI Large Rifle Benchrest primers and, using my Lyman 1200 DPS II powder system, charged 20 of them with 54 grains of Norma URP and another 20 with 58 grains of H4831SC.
When I went to seat the 180-grain Nosler Ballistic Tip bullets, I made an interesting discovery: The magazine box of the 84L is just barely longer than standard .30-06 overall cartridge length. Makes sense. Why make it any longer in a rifle designed for trimness and light weight? But in practical terms, it prevented me from seating bullets out to kiss the rifling--a trick that has often gained me better accuracy. In fact, with bullets seated to just touch the rifling, my handloads were roughly a quarter-inch too long for the magazine box.
Sure, I could have single-loaded cartridges for an accuracy test, but in a big-game rifle, what's the point? Handloads need to fit the magazine and feed flawlessly from it. So I just seated all my handloads to standard overall length.
Results at the range were neither more or less accurate than the average factory load. Interestingly, though I got somewhat better groups with the H4831 loads, I found that the loads charged with Norma URP powder turned in much lower standard deviation and extreme spread numbers as well as better velocity. With more time and a bit of tinkering, I could have played with various charge weights and, I'm sure, found a load the Kimber really liked.
Mike Schoby--who recently went hunting in Africa with a Kimber 84L--allowed me to test some handloads in his rifle, too. This time I used only Norma powder and topped it with 168-grain Sierra MatchKings, and one load turned in MOA performance. It was clear that with a little further load development Schoby's rifle would shoot sub-minute groups.