GUNS Magazine Is Your Scope Square?

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D’Arcy Echols fashioned and now markets this target to
help orient scope reticles easily and precisely.

Long ago I shot rimfire matches with a friend whose offhand position put the rifle in a steep cant. The 50-foot distance and his position were the same for each shot, so what did it matter his scope was at 11 o’clock to the bore? The sight-line intersected the bullet’s path at 50 feet. He shot good scores.

A scope rotated in the rings so its vertical wire tipped to 11 o’clock is likewise harmless. You could spin it so a crosswire appeared as an X, and center the bullseye every time at the zero distance.

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A plumb bob in front of this backing board shows “true vertical.”
The target is aligned with its cord.

But …

The rub comes when your target is not at the zero distance. If the reticle is plumb but offset from the bore, the bullet will fall parallel to it but meet its image only at the zero range. Think of side-mounted scopes, common on the top-ejecting deer rifles of my youth. Bullet and sight-line converge to zero range, then diverge beyond it. But in the lateral plane there’s no gravity-like force pulling them together again.

Shooting far, you want the scope at 12 o’clock on the rifle, the reticle absolutely vertical. Absent wind and setting aside spin drift and Coriolis effect, the bullet should fall directly behind the wire but attaching a scope to ensure it is “squared” is not as easy as you might think.

“It kept me up nights,” said D’Arcy Echols, as if building his exquisite hunting rifles left nothing to the imagination. “The solution should have come sooner. Gravity has been around awhile.” But his device wasn’t intuitive. Or a copy. He’s been awarded two patents.

A week later I stepped into his shop, trying to look as if I knew my way around machine tooling. Sensing my discomfort, D’Arcy started at my level, with a length of parachute cord and a catfish sinker. “At long range, a reticle’s vertical wire must align with the tug of gravity. If you use a mil-dot for elevation and the wire is not vertical, you’re aiming to the side of the bullet track. If, instead, you use the elevation dial to maintain a center hold, the principle still applies. The reticle must track vertically.”

A couple for whom he was building rifles had set him on the path to bring scope reticles quickly vertical to help ensure first-round hits at long range. “My clients were to hunt sheep in one of the ‘stans.’ The outfitter had advised them shots could come as far as 600 yards.” Echols dangled the catfish sinker. “Hence my plumb line. And target.” He unfurled a long paper checkered with MOA squares. Two bold vertical stripes in its center intersected twin horizontal stripes near top and bottom of the grid.

Now, you can align any scope’s wire on a vertical stripe by rocking the rifle or twisting the scope in its rings. Neither trick ensures the rifle is level or the scope is at 12 o’clock, or consequently, the bullets will descend behind the wire.

“To level a rifle,” said my friend, “you need a flat surface, a base-line.” Flat surfaces on rifles are scarce. Flat-bottom receivers on early bolt rifles are flat like Kansas — not crenulated or mountainous, but not truly flat. “You can make a receiver flat on top by adding a rail or a scope base, but plenty of scope base holes are off-plumb and off-cen

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In D’ Arcy Echols’ fixture, this Model 70 is ready to level, using
the rest feet to move the bubbles on the bar.

Not all flat-bottom receivers are flat, but the recessed flat behind a Model 70s
recoil lug serves for the mounting block. The leveling bar indexes off the action rails.

The Solution

Echols found the flat surfaces he sought inside the receivers. “Action rails are uniformly broached on a plane perpendicular to features that define the vertical in bolt rifles. They’re independent of external contours.”

Thus, he milled a steel bar which slid into a Remington 700 action and protruded over its tang. He then installed a tube bubble level crosswise at the rear of the bar, a circular bubble just in front of it. Floating ball bearings in the bar hold it firmly and snapped into place. Removal required depressing the bolt release.

Satisfied, he made a similar bar to fit a Winchester 70.

D’Arcy hung the sinker in front of a 100-yard target board at the local range. He tacked his target so its vertical stripes shadowed the plumb-line. “Over sandbags I leveled the rifle with the bar and rotated the scope in its rings, aligning the vertical wire with that pair of stripes. To check scope tracking, I fired at the lower stripe intersection, dialed 40 clicks up and fired again. Given quarter-minute clicks, I looked for the second group 10" up that stripe. Easy peasy.”

Then, using his shop skills, he revisited an idea that had once helped him diagnose a faulty scope.

He machined a two-piece, windage-adjustable alloy block for his Hart bench-rest, dovetailing its top to accept a V-block drilled and tapped to a round receiver’s front guard screw. For Model 70s, he made a flat block to fit behind the recoil lug.

A Remington 40x awaits a leveling bar (above, left). Note the windage screw
at the platform’s rear, for easy side-to-side alignment. A Hart benchrest to hold it all.

Clockwise from top right: AR-15 leveling fixture, Model 70
mounting block, V-block for round receivers.

Proof

Early next day at the rifle range, D’Arcy removed the stock from an Echols Legend rifle in .300 Winchester. “You can do the rest.” And I did, attaching the block to the receiver, marrying the pair to the dovetailed base and securing all in the Hart bench-rest.

I traded the bolt for a leveling bar and adjusted the rest to center the bubbles. Eye to the scope, I used the base’s windage screw to bring the reticle onto the stripe. They were nearly parallel. I fired a three-shot group. It centered the stripe. “Come up 30 clicks.” I did, and fired another trio. Predictably higher, that knot edged one side of the stripe. “Not close enough,” scolded D’Arcy. “You’re off half an inch at 100 yards. That’s 5″ at 1,000.”

Easing tension on the ring screws, I tweaked the scope so the wire matched the stripe perfectly — and had to repeat to allow for a slight shift when cinching the screws. Dialing down 30 clicks showed the crosswire holding true laterally. “Not all scopes track true,” Echols pointed out. “Dialing up for distance, you must ensure the mechanism will change elevation only.”

D’Arcy also showed me a long alloy block he’d just fashioned for AR-15 receivers. “Turns out the base-line on an AR is the belly of the upper. So I designed an external block that hinges to the upper. Use it to level the rifle as you would the bar in a bolt rifle.”

The AR block functioned as well as the bars. I marveled at D’Arcy’s ingenuity. Plumb is a simple concept. Getting a rifle receiver and its scope reticle plumb begs a clever mind.

D’Arcy Echols plans to market bars and fixture components separately –‑ targets too — so shooters can tailor this system to their needs. Everyone deserves a square scope.

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