Long-Range Shooting with the AR-15

By Glen Zediker published on in Ammunition, Firearms

For the AR-15 shooter, what does “long range” mean? It’s subjective. For someone who is usually popping away at 100 yards, then 300 yards may seem distant. If a shooter is comfortable at 300 yards, then maybe 500 or 600 qualifies as far; an experienced NRA High Power Rifle competitor might set the cap at 1000, and there are a few who take it farther than that. In my way of looking at it, we hit the edge of the world when a bullet drops below supersonic velocity. Until then, it’s possible to keep shots on the intended target at any distance.

Realistically, a properly configured AR-15 is easily capable of good performance at 500+ yards. Good performance means it can hit a 1-foot-square target all the time. Competitive shooters can cut that standard in nearly half (the X-ring on an MR1 600-yard NRA High Power Rifle target is 6 inches, and high X-counts are commonplace among more skilled shooters).

Of course, it wasn’t always that way…

In the early 1970s, shooters figured out that the AR-15 rifle itself could be made to perforate targets accurately. The Rodman Laboratories (Rock Island Arsenal) rifle experiments paved the way for civilian intervention, and that was essentially custom rifle builders duplicating the free-floating forend tubes engineered to float true match-grade barrels.

Heavy Barrel AR-15

A properly outfitted AR-15 is capable of very good accuracy at distance. The key elements for success are barrel and bullets.

Early on, what stopped progress at extended ranges were bullets. At the time, bullet makers had yet to consider the .224-caliber bullet worthy of commercial refinement beyond 200 yards. About the best available projectile at the time was a Sierra 63-grain design. One of the Rodman Labs guns recorded a nice 4-by-5-inch 600-yard group from a handload using that bullet, spun through a Hart 1:9-twist barrel. Those guns also had the first (that I know of) flat-topped upper receivers, done so that match sights could be mounted.

DPMS AR-15 barrel with twist rate stamped into it.

When using heavier, longer bullets, make sure the barrel twist rate is at least this quick.

In the early 1950s, it was theorized that a smaller, higher-velocity projectile could be the hot ticket to the field hospital for our adversaries. In 1968, the Army’s SALVO project drew blueprints for a 68-grain .224-caliber bullet, which was essentially a proportionately miniaturized .308-caliber service bullet, to test the theory. Although this was not a match bullet, it was an effort to establish a .22 as a viable longer-range round. A (then) new company in California, Sierra Bullets, produced the prototype SALVOs.

So, some 40 years ago there was a sub-moa “sub-caliber” 600-yard rifle and a round to accompany it, more or less. I don’t know that a Rodman gun ever met a SALVO bullet; who knows, they may still be sitting on the same shelf together.

Genuine SALVOs produced by Sierra Bullets

Here are some prize possessions in the author’s AR-15 historical collection: Genuine SALVOs, produced in 1968 by Sierra Bullets. Sure enough, they don’t look like match bullets, and they aren’t; the idea came back to life many years later by the same company that manufactured these.

Nothing of note happened with the SALVO concept until 15 years later. Sierra released its 69-grain MatchKing™ .224 in 1984 and literally added length to the competitive potential of the AR-15. While not reliable for pinpoint gunning at 600 yards, two-thirds of a score was better than no score, but that’s about all that could be expected from an across-the-course trip with an AR-15. (By the way, that bullet still works well at 200 to 300 yards.)

Bill Davis came up with a new bullet configuration called a VLD, for “very low drag,” that was designed to give our boys a better chance in USSF 300-Meter competition. The original VLD was a .243, but the design, not the caliber, was what made it work. The result was an 80-grain .224 match bullet produced by Jimmy Knox and Carlene Lemmons of JLK from Davis-supplied blueprints. That was in 1990. This bullet, more than any other technical trickery, turned the AR-15 into a serious across-the-course tool.

6mm VLD Blueprint

The original blueprint supplied by Bill Davis to Jimmy Knox and Carlene Lemmons to produce the first true long-range .224 bullet: the JLK 80-grain VLD.

The VLDs look more like missiles than bullets, and accordingly, they drop and drift significantly less than conventional bullets of equivalent weights. They do this by virtue of a higher ballistic coefficient (or “BC,” which, mathematics aside, means less speed lost over distance). Sierra soon afterward released its own high-BC .224 profile in an 80-grain bullet. These bullets provided the .223 round cause for respect rather than ridicule. Compared to the commonplace 168-grain .308 Winchester load most service competitors were feeding their M1As, the 80-grain .224 bullet needed less wind correction. Of course, chamber specifications for VLD bullets need to be modified, and rifling twist rate, expressed as one turn in so-many inches (meaning how far the bullet travels before it makes a full rotation) needs to be a minimum of 1-in-8 twist for an 80-grain bullet.

Trio of Sierra bullets

Here’s a trio from Sierra that extends the length of the AR-15. From the left are bullets weighing 80, 77 and 69 grains, respectively. Unlike the relatively “spikey” VLDs—that tend to be sensitive to seating depths due to the extreme secant ogive configuration—the more gently tapered Sierras are an easier bet for improved long-range performance.

However, with the right configuration of barrel specs and bullet shape, the AR-15 is capable of enough accuracy to challenge the skills of nearly any shooter. We’ll cover more elements of setting up a successful long-range AR-15 in much more detail next time.

What’s “long range” for you and your AR? Let us hear from you in the comment section.

 

[gzediker]

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Comments (23)

  • Ed

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    Great article. Please give more on the rate of twist and bullet weight combo

    Reply

    • James Lilley

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      Was using a 10x40x50 using a 115gr bullet. Now changing scope set up as the scope I was using is a little too much for my 6.8 spc

      Reply

  • Glen Zediker

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    Folks, sorry for the delays in responding to posts. I’m kind of new to the blog thing…

    One question about the “why” for .223 longer range interest is pretty much because we had to shoot it, in NRA High Power Rifle Service Rifle competition. The idea was to equal an M14 or M1A at 600 yards, not to define a new standard for long range rounds. It’s done pretty well.

    I hope to have some more published here soon that might give some more ideas on ammunition, cartridge specifics.

    Reply

  • Glen Zediker

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    (I mistakenly also answered with this to another post, but I meant to put it here…)

    Question about the “why” for .223 longer range interest is pretty much because we had to shoot it, in NRA High Power Rifle Service Rifle competition. The idea was to equal an M14 or M1A at 600 yards, not to define a new standard for long range rounds. It’s done pretty well.

    Reply

  • Glen Zediker

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    Right about the gain twist. That’s been done, and generally abandoned. The idea was to impart more and more spin as the bullet traveled down the bore. Problems were that it tended to damage some bullet jackets, put excessive obturation marks from the rifling, because the rifling wasn’t consistent.

    Reply

    • Richard wilson

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      I’ve been trying to get some re-load recipes for accuracy distance (paper killing) for 14 in h barrel, 1:9 twist. Any help? I have typically been shooting 55g NATO rounds. Nothing special, just having fun and u want to compete against myself with an A303 at about 300 yds (for now).

      Reply

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