An AR-15 Can Do Anything Well.
This One Does One Thing Great.
Story By Glen Zediker
Photos By Ichiro Nagata
upper with no forward assist and increased wall thickness. Its rail sits 1/2" higher
than usual. Gary Eliseo machined the Picatinny rail into an 11mm dovetail to
match the Anschutz rear sight mount, then machined a slot aft of the ejection port to provide clearance for a bolt knob to retract the carrier. The knob works better (opposite page, top).
However! The preponderance of NRA High Power Rifle competition doesn’t take place at 2/3/6. It’s done all around this country on “reduced” courses, and the majority are 100-yard. A very good while ago NRA recognized the issue and established reduced course provisions. Not every shooting community could afford their folks a full-length course. In my area there is one a little more than two hours away and another closer to four. The rest are overnight trips. I’m lucky, compared to many. There are areas with no reasonable access to 600-yard ranges.
I’m not snobbish over reduced-course shooting. I enjoy it and it’s not easier, not at all. The targets are scaled proportionally to their big brothers. Reduced courses are good training because environmental conditions are effectively removed from the usual High Power equation. The shooter can focus on shooting. I also have a choice of reduced course matches most any weekend of the year within an hour of home.
Now comes the problem the rifle here solved. If my “local track” is 100-yard courses, why am I shooting a full-length course rifle on them? That’s sort of like using a jackhammer to drive tacks. And the tack-driving part suffers.
I used to just lighten the bullet and also shoot a lighter load for reduced-course shooting. I think those are wise things. There’s no need to shoot an 80-grain bullet at 2,800 feet per second at rock-chunking distance. Also, such combinations won’t usually work too well on target. Long bullets and fast twist barrels don’t often shoot really small groups up close. Lightweight bullets with fast-twist barrels may perform poorly, too.
Reduced course targets are small. Some days they seem very small. The 100-yard reduced “600-yard” target has a .75" X-ring and 1.75" 10-ring. Right, most rifles will group smaller than that, but then there’s wiggle factor. Shooting a 20-shot group under 2" prone with iron sights takes a pretty good hold. I have heard way too many “cuzzins” say they can shoot a lot better than that at 100 yards. They (rarely) come out, but have yet (ever) to come back.
I’d had an idea for years to build a rifle just for these events, and I finally did it. This reduced-course rifle is my daily driver. Stood to reason it ought to be made up the best way it could be. My idea was not only to adjust obvious specs to maximize performance at short range, but also to take full advantage of the opportunities these changes presented for improving my relationship with the rifle. “Take full advantage” is such music to my ears. I can smell gold-plated plastic through 3' of concrete.
I first picked a builder, and I chose Gary Eliseo. Gary is a High Master ranked NRA High Power Rifle shooter and a thoroughly competent machinist. These two criteria are the “rules” for a project such as this. Your gunsmith really needs to be a machinist — someone capable of producing parts and unafraid of metal removal. I know it’s not necessary for a builder to be a hard-holder to make a great gun, but in this project it was productive to be able to discuss solutions to some of the problems I wanted to work around. If a builder doesn’t understand what I’m telling him is a problem, he’s going to leave the solution to me or, —worse — not really understand what I want well enough to help me attain it. The customer is not always right, but he needs to be happy, and that’s the point.
I had a few main ideas we needed to make work. Since the rifle didn’t need a long barrel I wanted to use the weight loss to add and move weight where and when I wanted it. I envisioned the most fit-tunable AR-15 I could have. I am a big believer in making a rifle fit the shooter. My rear sight mounting would give me the head position I shoot best with. I wanted a rear sight with extra-fine graduations to help better center groups. I wanted it bristling with trickery if only for the whole tailgate thing. Oh, yeah, and I wanted it to shoot teeny, tiny groups. This last goes first.
Make It Shoot
I wanted the smallest groups I could get from an AR-15 at 100 yards. Being fully aware that an AR-15 is not a Benchrest rifle, I still wanted to borrow and apply what I could from “them” to get what I wanted. Notice the capital “B” meaning the sport, not the shooting platform. Their game is group size. Teensy, weensy group sizes. Those who use 22-caliber tend to shoot 52-grain bullets through a 1:14" twist barrel. They also tend to choose a 22" barrel. Well, me too then.
I chose a Krieger barrel for this rifle, and I choose Krieger barrels for all my rifles, when/if I can. I got a stainless steel 1:14" twist, 4-groove. Krieger barrels are cut-rifled. There are pros and cons to any rifling process I won’t debate here, but one point is using a single-point cutter makes it possible to rifle a barrel after it’s been contoured, as was this barrel. When barrel diameter is altered on the outside, it also changes on the inside. AR-15 barrels by necessity have steps cut into them, and these are usually square-shouldered and significant.
Do The Twist
The 1:14" twist was “a little edgy,” said some, and suggested 1:12" to accommodate more bullets, but I had no plans to shoot anything but a custom-made 52-grain flatbase. First thing to understand about twist rates is they are dependent on bullet length — not weight. Even some boattail 52s are a little long for superb results in 1:14". Benchrest shooters look for the minimum rotation still stabilizing the bullet — puts it to “sleep” is how they say it. I would recommend 1:12" if you want to shoot a wider range of light bullets including 55-grain ball ammo.
Since bullet velocity wasn’t a factor, ballistically speaking, barrel length could have been shorter. I had first thought to install a 16" to 18" barrel to minimize the time the bullet spent inside the barrel. That’s good because any movement on firing has less effect on shot placement, good or bad.
Two things changed my mind. The first was why Benchrest shooters use 22". They once used 18" barrels a full diameter (parallel contour). Their thoughts then were shorter, stiffer barrels were best. Well, someone found out a little longer barrel seemed to shoot better in the wind. The reason, supposed, was having the bullet in the barrel longer made the bullet more stable. It wasn’t a matter of twist rate, or velocity, just more rotation time.
A normal consideration would have been function. Short barrels in AR-15s can be problematic. This wouldn’t have become an issue in this rifle because gas port location could have been the same no matter what. Weight, however, would have gotten too far back from the muzzle for the rifle to hang right, even with increased barrel diameter.
Gas port location was moved ahead 1/2" over the blueprint location and hole size is .090", which is a little larger than standard. Early short stroke problems were quickly eliminated by trimming a couple of coils off the buffer spring, and was also the impetus for Gary reaming the port to a little larger diameter. Now, moving the port forward didn’t cause the short stroke. Port hole location and port hole size are not directly offsetting or complimentary factors. Disregarding the influence of propellant burning rates, the size of the port determines how much gas gets into the system and port location determines when it gets in. It’s still better to move the port ahead to delay bolt unlocking.
Barrel specs were simple. Full diameter, 1", to the gas block shoulder, then to .820" from there to the end of the barrel. There is a 1.5", .75" parallel section machined at the muzzle to accommodate a clamp-on tube or front sight base mount. Most competitive shooters don’t use screw-mount dovetails because clamping allows the front sight to be moved to level against the back sight. I use .75" diameter because I have many things that size.
One of the biggest changes I made is this rifle is not .223 Remington. After eyeballing Benchrest tools I realized no one used it. The cartridge is not considered in the group of “accurate” rounds. The dominant force in Benchrest is 6mm PPC. It’s based on .220 Russian and has a 30-degree shoulder, 1.5" case length, and .445" case head diameter. I chose .222 Remington, aka: Triple Deuce. Why not go in locked step with Benchrest and go PPC?
I have an AR-15 chambered in .22 PPC. It’s a full-course rifle and the whole idea (to me) was to get about 200 fps more over .223 Remington and be able to shoot 80- or 90-grain bullets from the magazine, with room left over for bullet seating flexibility. I didn’t go with it here because my PPC wasn’t the easiest rifle to get to work. Mine eventually worked, but the case doesn’t want to feed as well as .223 Remington. Next, the idea was to shoot short bullets, not long ones (compounding the feeding problems). Before the PPC, the .222 was pretty much the king of Benchrest. It still holds one record after its fall from favor 25-plus-years ago. No one ever said it didn’t shoot.
The .222 is essentially a short .223 Remington (historically, .223 is a long .222). It was easy to make work. As a matter of fact, Colt factory-chambered some of the old SP1 rifles in .222 Remington for export to countries prohibiting sales of rifles chambered for a military cartridge.
Why is the .222 better for me? Its shorter length means a bullet can be seated to touch the lands and stay under magazine cartridge overall length restrictions. Another is the .222 has a considerably longer case neck. That’s great. The whole idea is avoiding seating the bullet into the case shoulder area, and there are several reasons for that (all good) .
I didn’t spec a tight-neck reamer or in any way reduce chamber dimensions, which a Benchrest shooter surely would have done. Across-the-course rifles, semiautos in particular, have to function and a slightly more generous chamber has zero measurable effect on group size, especially when we’re full-length resizing cases.
I like a lot lighter rifle for offhand than I do for prone. The shorter barrel made it possible to lose some weight down to what I think is ideal for offhand (11 pounds) without sacrificing elsewhere. With their 26" barrels, my full-course rifles finish up at about 13 pounds. For prone I prefer a heavier gun. The lighter weight let me use an adjustable fore-end weight system from a smallbore free rifle Eliseo mated to the handguard rail slot. I set the weight to be what and where I want.
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Bullets are Bart’s. Saying any bullet is the best might get a scientific calculator chunked at you at a Benchrest match, because they are not going to agree with anything so pointed (hah!) and are always looking for the magic bullet. Many competitors make their own. Bart’s are handmade, actually win matches and are available in reasonable quantities. They are way-on better quality than any other brand. I chose Lapua brass because it’s comparatively flawless. Virtually no case prep is necessary. Operating load is 21.5 grains Viht. N133, OAL cartridge length 2.130", WW primer, Bart’s 52-grain bullet, speed about 3,050 fps.
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I finally got around a problem we encounter on 100-yard reduced courses — getting centered on the target. To be really centered requires a rear sight with finer graduations than those used on full-length courses. The best sight with the finest graduations is an Anschutz. With standard knobs it produces approximately 1/7-minute-of-angle click stops. That means it takes about 14 clicks to go across the 10 ring instead of 7 on a 1/4 MOA sight. By comparison, a 1/2 MOA sight virtually eclipses the X-ring in only one click.
This unit is tough enough for High Power, especially on a rifle recoiling as little as this one. The sight I chose is cant adjustable. I don’t hold a rifle vertical when I shoot (it fits me better when I lean it over). If the sights can be level when the rifle is canted, it’s exactly perfect.
The problem was no one made a base mating an Anschutz 11mm dovetail to a Picatinny rail, and I didn’t suspect there was any reason anyone should. Eliseo decided the best way to do it was turn the upper into an 11mm dovetail rather than make a custom base. I can position the rear sight anywhere along the rail.
I didn’t have to worry about moving rear sight elevation much since the rifle was not going to travel from one yard line to the next, and also because I was installing an elevation-adjustable front sight. I set the rear sight height where I want it and keep it there.
The Centra front sight is total overkill. It’s the best front sight I’ve yet used, but is wasted on a 100-yard course, of course. It’s adjustable for elevation using click stops (1 MOA) just like a rear sight. The idea is to change yard lines adjusting elevation at the front rather than the rear allowing you to keep the same head position (cheekpiece height). Great idea. Again, for this rifle, the adjustable front sight allowed me to determine rear sight height without worrying about its influence on shot impact location.
The trigger in the rifle photos is a Jewell. The contraption you see attached to the outside of the receiver is part of a KNS trigger pin package. KNS pins are designed to be locked into place. That prevents any possibility of rotation. Rotation spoils trigger action. KNS pins also feature lube recesses and, as well as would be expected, measurably perfect concentricity and sizing. KNS pins are, in my experience, mandatory for use with Jewell triggers. I plan on replacing it with a Geiselle in the future. The Geiselle unit reduces lock time over the Jewell by half.
The bolt carrier was drilled and tapped for a handle (bolt knob). This was done for two reasons, although neither was strictly necessary. With some adjustable stocks, the cheekpiece blocks charging handle operation, and a bolt knob has been the standard solution. Gary’s stock design makes it possible to rotate the cheekpiece out of the way and use the charging handle, but having the bolt knob just means I don’t have to. I also like the knob. After you try one you won’t like charging handles anymore. To make the knob work, a slot had to be milled behind the ejection port to make room for it to track. No step for a stepper. The knob has to be removed to remove the bolt carrier, but it’s easy to unscrew.
The capacity to adjust how a rifle fits defines how well I or anyone else really gets along with it in competition. The reason it’s so important is shooting across-the-course is done from a human platform. We have a lot of appendages and inefficient levers and pudges and the like, and setting up a rifle to mold in to someone’s self is a truly eye-opening experience. This stock can be twisted and tweaked until it touches you where your related body parts are located when you’re in a position you like.
“Fully” adjustable means length, buttplate rotation, height, cast and cheekpiece height. Eliseo’s cheekpiece design is as far forward as it can possibly get. Many are too far back from the receiver and force a “pulled back” head position.
Combined with the stock and weight adjustment, I can rotate the fore-end on this rifle to suit, and the Centra adjustable handstop gives yet another opportunity to experience bliss. It takes a while to get all this right, but it’s worth it.
So how’s it shoot? Pretty well. How is it to shoot? Outstanding. Out on a limb, I’d say it’s probably the best AR-15 I’ve yet shot because it was designed with such a specific purpose in mind. Going over the top didn’t hurt at all — virtually no compromises. I was able to match this rifle more closely to an “ideal” in everything that matters to shooter performance, not just rifle performance. This one fits me better than any AR-15 I own.
My full-length course rifles shoot outstanding groups at full distance, yet are over double the group size of this little gun up close. It was pointless to compare them at distance. Here’s a good example. My “number one” NRA Service Rifle has a 1:6.5"-twist Krieger barrel for 90-grain bullets. In testing, its 600-yard group was 4.9" vertical for 10 shots. Pretty good for a smokepole. At the 100-yard line fired it with that load the group size was .850" vertical. That’s not very good. In contrast, the best groups I’ve shot so far with the little gun have been .185"x .111". That’s good grouping — as good as a Benchrest rifle will do, but not the best one can do. It, however, is way-on better than I thought I’d ever see from an AR-15.
So what’s all this flatbase bidness? Flatbase bullets aren’t in themselves better than boattails, but they are shorter. That’s why Benchrest shooters use them. See, 52 grains with no boattail is a shorter bullet allowing use of a slower-twist barrel and less orbiting in flight.
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