Accuracy from Alignment
All Preston Pritchett likes in a long-range rifle shows up in the long-action, 16-pound Remedy he loaned me. Equipped with a two-pound Jewell trigger and a 4.5-14X Leupold LRT scope, this .338 Lapua put my first three factory loaded Hornadys into a .2-inch hole.
“It’s just 100 yards,” shrugged Pritchett.
Indeed. But not all long-range rifles shoot that well up close. “Groups can improve as bullets go to sleep,” says D’Arcy Echols, who builds the most consistently accurate magnum hunting rifles I’ve seen.
In 1996, Echols was turning out four exquisite, walnut-stocked sporters a year from his Utah shop. To produce more affordable rifles, he committed to a mold for a high-end synthetic stock with classic lines.
His Legend is a Winchester Model 70 with many refinements: re-machined receiver belly, bolt face, receiver face, recoil lug seats and lugs; lapped locking lugs; new pins in the trigger, ejector, and bolt stop to remove play; reconfigured ramp and rails; stainless five-round magazine box and follower engineered to the cartridge; custom bottom metal; steel scope rings machined to receiver contours and secured with five 8×40 screws.
Echols attributes the performance of his rifles to tight tolerances. “I surface-grind receivers on a mandrel between centers, so each is within half a thousandth of parallel with the bore.” A special gauge ensures perfect bore/chamber alignment. Most Legend rifles weigh around nine pounds with mid-weight, 26-inch Krieger barrels in .300 Weatherby, “though we’ve built some .300 Winchesters.”
Echols lets bullets coast just .125-inch before engaging the lands, a third of the start they’d get in Weatherby rifles. “The throat—that unrifled section of bore in front of the chamber—can be short or long, parallel or funnel-shaped,” he explains. “It allows the bullet shank to protrude from the case without engaging the rifling, and it gives the bullet a running start. Funnel-shaped throats, from blackpowder days, allow more bullet waggle than do parallel throats .0005-inch over bullet diameter.”
The funnel throat for the .300 Winchester Magnum is .3-inch at the rear of full-depth rifling, .315 at the case mouth. A parallel throat that allows the bullet to slide like a piston offers more guidance than does a tapered throat. But because bullet diameters vary, parallel throats must not be too tight.
The closer a bullet’s fit in the throat, the less critical is throat length.
“A long-throated rifle is said to have free-bore, but there’s no dimension that defines that, so the term is really meaningless,” D’Arcy says. “Besides, the most critical factor in accurate shooting at long range is the shooter.”
Texas gunmaker Charlie Sisk agrees.
“Most rifles shoot better than most shooters,” Sisk observes. “You can’t flinch. Also, the rifle must be held exactly the same every time. The striker sets up vibrations as it falls, before the bullet exits. Pressure from the rest and your hands affect those vibrations, as well as barrel alignment as it vibrates during bullet passage!”