By Ron Spomer
So your hot new rifle isn’t exactly living up to your expectations? Not exactly shooting lights out?
Well then, accurize it.
Accurize may not be a legitimate word, but rifle nuts know what it means – “do whatever it takes to make your rifle shoot MOA or better.” And it doesn’t take a gunsmith to do it.
Before messing with the hardware, define accuracy for YOUR needs. Do you really need a 1/2 MOA shooter? A rifle that groups three-shots into a two-inch circle at 100 yards, every time (2-MOA) is more than accurate enough for deer out to 300 yards. Really. A 2 MOA rifle will put each shot no more than one-inch from where you aim at 100 yards, two-inches at 200 yards, three-inches at 300 yards. The average deer’s chest/vital area is at least ten inches in diameter. Aim for its center and you aren’t going to miss if your bullet lands three inches from where you aimed.
But of course, no real marksman wants to settle for a 2 MOA gun! Coyote, woodchuck and prairie dog hunters shoot at six- to two-inch vital zones. Sometimes those tiny targets are 600 yards away. For this, one-MOA is not good enough, and one-half-MOA barely makes the grade. So, you establish your level of accuracy, then work to build it.
First, clean the barrel interior before test-firing for group size. A good cleaning has turned dirty, three-MOA rifles into one-MOA deathrays. After cleaning with the usual powder solvent, clean again with a copper remover solvent (CR-10, M-Pro 7, Gunslick Copper-Klenz, Montana Xtreme, etc.) and vigorous scraping with a tight Brownell’s Brass Core Bronze Brush on a one-piece Dewey or Gunslick rod. Some shooters make 10 passes with the brush for every shot fired. I usually push and pull 50 times, adding additional solvent to the bristles every 10 passes or so before pushing out the slurry with a patch.
After the black powder fouling has been removed, the slurry should come out blue. This is the oxidized
copper. In rough bores, J-B Bore Compound, a fine-grit polish, helps cut through the copper fouling and speeds things up. Dab the gray paste liberally on the bore brush and work that rod. Flush this out with more copper solvent. You’re finished when, after your last treatment of solvent has worked in the barrel for five minutes, the next patch comes out white. Run a light oil patch through, then a dry patch to remove excess oil and shoot a 3-shot group.
If that cleaning doesn’t give you enough accuracy, check the shooter. Often its the person behind the trigger that’s inaccurate. Some guys shoot offhand or off truck hoods and then complain about the rifle being inaccurate. Come on guys, let’s be fair. We must isolate the launch pad (the firearm) from jerks (that’s us) and jerking as much as possible. Use a solid bench (not a card table) and sandbags, a Caldwell Lead Sled, Harris Bipod, Shooters Ridge Gorilla Bag, MTM Shoulder Guard Rifle Rest or the like to minimize all vibrations. And rest the midsection of the forearm stock, NOT the BARREL, on the support.
Barrels vibrate violently when a cartridge ignites, and touching them changes bullet impact. Don’t press down on the barrel or scope, either. Hold the forearm stock loosely if at all and don’t go white knuckled on the pistol grip. This will introduce torque and throw your shots. Concentrate on the sight picture and try to pull straight back on the trigger without disturbing the rifle.
Have a buddy try a group or two to see if he shoots better than you. I’ve seen groups shrink in half with different shooters.
If accuracy remains poor, suspect your scope and mounts before anything else. Screws really do back out. The bases might not feel loose, but tighten them anyway. Ditto the ring screws. A dab of blue #242 LocTite prevents screw-loosening. If that doesn’t improve things, try a different scope, one you know is accurate. Yes, scopes can be inaccurate. Cheap metals can wear and stick internally. Erector tube springs can weaken and become erratic. Excessive windage or elevation adjustments can push tubes so hard against springs that they cannot hold zero shot after shot.
Excessive internal adjustments to get on target means you should remount and bore sight with windage adjustable bases (Leupold, Burris, Conetrol, Millett, Redfield.) Scopes work best with the reticle close to dead center.
Fourth, try different ammunition/bullets. Some rifles shoot one particular combination of case/primer/powder/bullet accurately and no other, so experiment. Try different brands, but also different bullet weights within each brand. Ideally you should start each test group with a clean barrel, but this isn’t mandatory. One exception might be when you test monolithic bullets such as Barnes TSX, Nosler E-Tip and Hornady GMX. They are most accurate from barrels free of other bullet fouling.
Fifth, re-balance the barrel. Browning’s BOSS does this. That cylinder at the muzzle can be turned in and out until its weight changes barrel vibrations for best accuracy. The idea is to turn the bullet loose at the split second the muzzle stops between vibration cycles. The Limbsaver De-Resonator, a rubber-like collar you slip over the barrel, works much like the BOSS. Adjust its position until you get maximum accuracy. I’ve cut group size in half with one of these. It ain’t pretty, but it’s cheap accuracy.
Sixth, re-crown the muzzle. The bevel at the muzzle must be smooth and consistent or gases will jet around the exiting bullet unequally, destabilizing it. A gunsmith can hone this smooth and precise in seconds. Countersinking the crown protects it from further damage.
Seventh, check the rifling lands at the throat or leade. You’ll need a Hawkeye Borescope to see this internal section of the barrel just ahead of the chamber where it ramps up to the rifling. If this area is lopsided, it was reamed improperly when the barrel was chambered.