April 7th, 2012
This past weekend, Forum member Ron Boyd shot a 1.462″ five-shot Light Gun group at 1000 yards in an IBS benchrest match at the MidWest Benchrest Club in Yukon, Missouri. Ron shot a 6mm Dasher with Bartlein barrel and PR&T stock. Ron’s 1.462″ group is 0.065″ off the existing IBS 1000-yard Light Gun record. Ron’s group also happens to be .011″ smaller than the current NBRSA 1K Light Gun record, 1.473″ shot by Bill Schrader in 2002. (But this is not counted by the NBRSA since Ron shot in an IBS match.) Ron’s group was shot in the first relay of the day, in good conditions. The group had three (3) shots clustered in under one-third inch (0.03 MOA)!
This is truly a spectacular achievement. We think this has to been one of the smallest five-shot groups ever shot at 1000 yards, and probably the smallest ever with a 6mm cartridge. At 1000 yards, 1 MOA is 10.47″. This means that Ron’s group measured in at 0.1396 MOA! To give you an idea of how small Ron’s group really was, at left is a 1.462″ circle shown at 100% scale, along with a quarter at 100% scale.* The circle represents the center-to-center distance of Ron’s five shots at 1000 yards. Total vertical dispersion was just under 1.2″ for five shots. The vertical for the top four shots (measured with OnTarget software) was just 0.398″! Shown below is a flat-bed scan of the actual target. Notice the tight cluster of 3 shots touching. That’s a dime in the photo added for scale.
Ron Boyd’s 6mm Dasher Load
Ron loaded a stout charge of Long Range Match surplus powder with Spencer 103gr bullets seated about .010″ OFF the lands. The bullets were “right out of the box”, NOT pointed. This powder has burn-rate characteristics very similar to Alliant Reloder 15, and Ron used his regular RL15 charge, adjusted by half a grain or so. Ron was using no-neck-turn “brown-box” Lapua 6BR brass formed into the 40° improved 6mm Dasher case. The unturned, loaded case necks measure about 0.2695″, yielding .0015″ total clearance in a 0.271″ chamber. The brass used for the 1.462″ group had seven previous firings. Ron anneals his brass after every firing using a Benchsource annealing machine. Ron told us: “The Benchsource is the greatest annealing machine there is, as far as I’m concerned.” Ron ultrasonically cleans his brass and then tumbles his brass after the ultrasound process. He does NOT use an internal neck lubricant. He does NOT uniform his primer pockets and he does NOT ream his flashholes. Ron believes this load was running “right around 3000 fps”, but he has not chron’d it yet using the new Bartlein barrel.
Ron Boyd’s 6mm Dasher Light Gun
Ron’s 17-lb Light Gun featured a BAT SV Action, Bartlein 30″ 1:8″ twist, 0.237″ land barrel, and Precision Rifle & Tool “Hammerhead” benchrest stock with 5″-wide wings in front. This stock weighs 4 lbs 1 oz. with an aluminum butt plate and is about 36.5″ long with integrated rails on the bottom of the “wings”. Ron’s friends Rich Griffin and Jerry Kloeppel did the chambering and bedding. Ron recently put the Bartlein barrel on the gun. Ron estimates that the barrel had only 40 rounds through it when it produced the 1.462″ group. Ron tells us: “This new barrel is great, and the 5″ PR&T stock really works. I luckily pulled the trigger at the right time.” Ron told us that this rifle shot in the high ones/low twos at 100 yards during testing.
PR&T Hammerhead Stock (catalog photo)
*The circle and quarter should appear “true size” when viewed at the most common monitor resolution. If you are running a higher resolution on your monitor, the illustration will appear small than actual size.
Share the post "Ron Boyd Shoots 1.462" 5-Shot Group at 1000 Yards"