204 Ruger AR Loads

My Mossberg MVP Varmint in 204 Ruger has effectively rendered my custom 22-250 Remington obsolete. Yes, the 204 Ruger will do anything the 22-250 can do, but with less bluster and powder consumption. Blame it on traditional 1:14 to 1:12 rifling twists and the light bullets/low ballistic coefficients this limits them to.

Don’t believe it? Here are real 500-yard/10-mph crosswind numbers derived from a trusted ballistics calculator while using like-label Sierra varmint bullets (all other factors remaining equal). The 22-250 Remington with a 40-grain BlitzKing (.196 BC at 4,000 fps) has 39.1 inches of drop and 37.6 inches of drift. The 50-grain BlitzKing (.248 BC at 3,800 fps) drops 37.4 inches with 29.4 inches of drift. The 204 Ruger with a 32-grain BlitzKing (.221 BC at 4,100 fps) drops 34.9 inches with 31.6 inches of drift. A 39-grain BlitzKing (.287 BC at 3,750 fps) drops 32.7 inches with 23.8 inches of drift. These are actual loads tweaked for accuracy, and small-varmint tested. All are delivered at velocities a step below maximum.

Tiny, frangible 204 bullets delivered at scorching velocities dramatically dismantle burrowing rodents and provide “dead-right-there” impacts on larger rockchucks and coyotes. The 204 Ruger is accurate and offers pleasant all-day shooting through negligible recoil and relatively low muzzle blast. Of course, it’s among a select few varmint cartridges that can be stoked to touch or best 4,000-plus fps. Such velocities can lead to premature barrel wear, so when a barrel becomes hot to the touch, set that rifle aside temporarily.

The Hornady/Ruger collaboration was released in 2004, based on an “improved” 222 Remington Magnum case with the shoulder bumped slightly forward and sharpened from 22 to 30 degrees. It provides a five percent case capacity improvement over the 223 Remington and produces a cartridge that thrives on a wide variety of medium burn-rate propellants. A SAMMI maximum overall length of 2.26 inches makes the cartridge AR compatible.

An AR-15 chambered in 204 Ruger is the topic of discussion here, a Rock River Arms Varmint A4 LAR-15M 204R. I’ve long been curious about this rifle as a serious varmint rig. A 10-pound Rock River Arms (RRA) Varmint A4 223 Remington tested a few years ago shot sub-half-inch groups with select handloads. Its soft-recoiling demeanor was welcomed after major surgery turned my shoulder a mite delicate at the onset of spring ground-squirrel season.

The LAR-15 204R includes a forged lower and A4 upper holding a 20-inch, fluted stainless steel bull barrel (.930 inch at the muzzle) with a 1:12 rifling twist. Other features include a low-profile gas block, RRA two-stage trigger (the test rifle’s trigger pull averaged 4.17 pounds), oversized Winter Trigger Guard, newly-refined handguard, a classic A2 buttstock and Hogue rubber pistol grip. The rifle weighs 9.1 pounds bare (around 11 pounds with scope and rings) and measures 38.25 inches long. It comes with a 20-round steel magazine (standard 223 magazines are compatible), RRA hardcase and a 1-MOA, 100-yard guarantee.

The rifle was fitted with a German Precision Optics (GPO) Passion 4X 6-24x 50mm scope set in 30mm Precision Hardcore Gear Black Opps tactical rings with an integrated level. The scope includes side-parallax adjustment and .25-MOA (100 yards) exposed turrets including PASSONtrac technology and 70 inches of vertical travel. The reticle is super fine for precision work in a welcomed second focal plane configuration calibrated at 24x. Double HD objective lens and GPObright coating technology deliver 99.7 percent light transmission. All GPO optics are manufactured in Germany and assembled globally before returning to Germany for thorough quality-control inspection. A free KENTON turret is offered with each.

Black Opps rings are 1.5 inches high and include an integral bubble level to reveal rifle cant without getting off the rifle while shooting. They’re milled from 7075 T-6 aluminum and are type-3 black hard coat anodized. Twin cross-slot clamping bolts and guide rails assure solid and precise Picatinny anchoring. A cartridge-style Sight-Rite Laser Bore Sighter by SME made zeroing easy.

Selected powders included Hodgdon’s H-335, H-322, H-4895, BL-C(2), Benchmark and CFE-223. Others included IMR-8280 XBR, IMR-4166 Enduron, IMR-4198 and IMR-3031. Western Powders’ Ramshot X-Terminator, TAC and Accurate 2520 and 2460 were used. Others include Alliant’s Power Pro Varmint and 2000-MR, Reloder 10x and RL-15; Winchester’s W-748 plus Vihtavuori N-140 and N-133 and Shooters World propellants shown in Table II. Choices were based on efficient velocity-to-pressure ratios or published data promising top accuracy. I intentionally shunned full maximum loads in diffidence to the auto-loading action.

Bullets were assembled to minimize design redundancy while maximizing bullet weight, construction/material details and price point options. Included are Hornady’s 24-grain nontoxic NTX (Non-Traditional eXpanding) and 40-grain V-MAX; Barnes’ 26-grain lead-free Varmint Grenade and 32-grain Varmin-A-Tor FBHP; Nosler’s 32-grain Varmageddon FBHP and 32-grain Ballistic Tip Varmint Lead-Free; Sierra’s 32- and 39-grain BlitzKing; Midsouth Shooters’ 34-grain Varmint Nightmare X-Treme FBHP; Berger’s 35-grain FB Varmint and 40-grain BT Varmint and Speer’s 39-grain TNT FBHP. Ballistic coefficients ranged from .131 to .287.

New Nosler brass and Federal Premium AR Match Small Rifle primers were used throughout. The Nosler cases held about 31 grains of water in contrast to Hornady (31.9 grains) and Federal Premium nickel (32.1 grains) cases on hand. All loads were assembled with Hornady Custom Grade Dies. RCBS offers Small Base Taper Crimp Die sets in its AR Series, if you feel the need. Of note, the stubbiest, flatbase bullets required generous neck chamfering to assure smooth seating, as they’re difficult to handle and prone to tipping and buggering brass necks.

During final sight-in firing proven bolt-action handloads, the LAR-15M easily shattered the accuracy promise with Nosler 32-grain Tipped Varmageddon and Sierra BlitzKing bullets, both loaded with 28.5 grains of Vihtavuori N-140 and Remington 71⁄2 Benchrest primers. Before the real bench work began, I’d planned an inaugural local varmint shoot around our first 65-plus degree day, belaboring fat Columbia ground squirrels out to meet a fresh spring.

Put simply, I was more than a little impressed with this AR’s accuracy. Shots were not extreme, averaging 225 to 250 yards. But when shooting prone over a bipod, the LAR-15M accounted for an 80 percent hit ratio despite light breezes. Recoil was so mild that when I did miss, getting back on target was nearly instantaneous.

This session also revealed some seating-depth issues related to detachable-magazine compatibility and feeding, reminding me yet again bolt-action ammunition can’t always be trusted to run in ARs. The Sporting Arms and Ammunition Manufacturers’ Institute (SAMMI) 2.26-inch overall maximum length should be considered absolute when loading for an AR.

With the fun over, the real work began, hitting the range to wring out various bullet/powder combinations sent into boring paper and numbers rung up on a Caldwell Chronograph G2.

The lightest bullet, Hornady’s NTX, started badly with Hodgdon’s H-335 by providing 1.5- to 2-plus-inch groups. Honestly, this is what I’d anticipated from this flyweight 24 grainer. But I was quickly proven wrong when 29 grains of Ramshot X-Terminator produced a .32-inch group at 4,264 fps and Hodgdon H-322 grouped into .33 inch with five shots at 4,247 fps. Barnes’ 26-grain Varmint Grenade also did fine work, the majority of groups measuring less than an inch, and the best measuring .52 inch pushed by 29 grains of IMR-8208 XBR at 4,048 fps.

Staple 32-grain bullets all lived up to Rock River Arms’ accuracy guarantee with at least one powder. The best groups resulted from Nosler’s Varmageddon flatbase hollowpoint (FBHP) over 28 grains of IMR-8202 XBR, Barnes’ Varmin-A-Tor FBHP pushed by 25.5 grains of Reloder 10x or 29 grains of Accurate 2520, and Sierra’s BlitzKing pushed by 27 grains of Ramshot X-Terminator or the same measure of TAC.

Nosler’s Ballistic Tip Lead-Free produced a sub-half-inch group with 29 grains of Alliant Power Pro Varmint, that .40-inch group the best with this bullet. Vihtavuori N-140 provided .60- to .81-inch groups with Sierra’s BlitzKing and likely deserves more exploration. Only Power Pro Varmint (29.5 grains) broke the heralded 4,000-fps mark with 32-grain bullets from the short 20-inch barrel. (The 204 Ruger generally sacrifices 40 to 50 fps for each inch of barrel subtracted from 24 inches). Also of note, IMR-4198 (listed as Nosler’s most accurate powder) failed to cycle the AR action, though accuracy was good.    

Midsouth Shooters’ 34-grain FBHP Varmint Nightmare X-Treme shot well, posting some of the tightest groups of the entire test. The best groups included a .48-inch cluster from 25.5 grains of IMR-3031; .34 inch from 26 grains of Hodgdon Benchmark; .35 inch from 27.5 grains of Accurate 2460 and a remarkable .21-inch group with 27 grains of A-2460. These affordable bullets run only 10 cents a pop when purchased in bulk, so are ideal for high-volume varmint shooters. They are also devastating on burrowing rodents. The only shortcoming is a low .131 ballistic coefficient in relation to longer shots and/or windy days.

Thirty grains of Hodgdon CFE-223 provided a .59-inch group with Berger’s 35-grain FB Varmint while IMR-4166’s best showing with this bullet was .82 inch. The “magic dust” proved to be Alliant’s Reloder 15 with all groups less than an inch and 27 grains producing a .48-inch cluster and 28 grains, .31 inch.

Based on experiences dabbling in 40-grain load development for my bolt rifle, I began this portion of the test with low expectations. I’ve always felt an oddball 1:11 rifling twist would be a good compromise between the standard-issue 204 1:12 twist (no doubt applied to benefit 32-grain bullets) and 1:10 that would likely produce ideal high-BC/40-grain results. This perception proved somewhat true with Speer’s 39-grain TNT (BC .202), though all loads printed, in the parlance of varmint shooters, “minute-of-squirrel.” I had to wait until the very end for more inspiring results. Reloder 10x provided the right stuff, with all charge weights clustering less than an inch, and 23.5 grains providing an impressive .34-inch group.

That’s all well and good, but I anticipated the higher BC bullets, namely Sierra’s .287 BC 39-grain BlitzKing and Hornady’s .275 BC 40-grain V-MAX wouldn’t be adequately stabilized. Wrong again – especially in relation to the BlitzKing. In fact, the 39-grain bullet produced a .51-inch group and four others measuring less than a half-inch. Hodgdon H-322 shined again, printing .31 inch and .40 inch with 24.5- and 25-grain charges, respectively. Vihtavuori N-133 produced .51- and .44-inch groups with 24.5 and 25 grains, respectively. The same company’s N-140 grouped .40 inch with 27.5 grains of powder.

Berger’s 40-grain BT Varmint performed well with IMR-3031, including .50-inch (24.5 grains) and .43-inch (25.5 grains) groups. Hodgdon H-335, Winchester W-748 and Accurate A-2520 turned in .84- to 1.59-inch groups with Hornady’s 40-grain V-MAX. I would’ve liked to try powders which produced the best Sierra BlitzKing groups, but deadlines loomed. Forty-grain bullet velocities hovered between 3,400 and 3,600 fps from the 20-inch AR barrel.

After completing these tests, handloading friends frequently ask, “So, which powders do I need to invest in?” Forced to pick but one, the easy answer is Hodgdon’s H-322. Given two options, I’d add IMR-3031, with Accurate A-2460 runner up. Ramshot X-Terminator, Hodgdon Benchmark and CFE-223, Alliant Power Pro Varmint, Reloder 10x and 15 and Vihtavuori N-140 and N-133 also posted sub-half-inch groups with various bullets. This is all a bit arbitrary, obviously, as combined with different bullets – and slightly better shooting on my part – any of the powders tested could’ve produced tighter groups.

The more important takeaway is to never assume anything. I was reminded – yet again – that quality ARs are capable of bolt-gun accuracy. Bantamweight bullets are capable of fine accuracy. Budget-priced bullets are nothing to get snooty about and the 204 Ruger’s 1:12 rifling twist is adequate for the heaviest bullets with the right load combination. Rock River Arms’ AR was ultra-gentle on the shoulder, provided good accuracy and was a real hoot in the field, which was exactly where that rifle was headed next.

Shooters World

Shooters World propellants was founded in 2012 by international shooters Karen and Ned Gerard, and Ken Johnson (an internal ballistics expert who spent 13 years in research and development at St. Marks Powder). Shooters World supplies American shooters branded LOVEX powders manufactured in the Czech Republic.

Shooters World offers 15 powders to cover pistol and rifle handloading needs, from the smallest to largest cartridges. Of those, Tactical Rifle and Match Rifle are best suited to the 204 Ruger. These are double-base, spherical powders that flow like water.

These powders arrived late in the game so there wasn’t time to include extensive loadings. Thus, I sampled Hornady’s 24-grain NTX, 32-grain V-MAX and 40-grain V-MAX, loading rounds a full grain below recommended maximums just to get an idea of performance potential.  

Tactical Rifle is a clean-burning alternative to Hodgdon H-335 and BL-C(2), formulated to optimize 55- grain bullet performance in 223 Remington/5.56mm and 147/150-grain bullets from the 308 Winchester/ 7.62mm rounds. The powder produces low residue and smoke and includes a flash suppressant. Tactical Rifle paired best with Hornady’s 32-grain V-MAX, grouping .51 inch and clocking 3,866 fps from the 20-inch barrel. It also posted acceptable results with Hornady’s 24-grain NTX at 4,140 fps and the 40-grain V-MAX at 3,535 fps. Tactical Rifle performed optimally with the lighter bullets.

Match Rifle was formulated as a long-range, flash-suppressed powder similar in burn rate to Accurate A-2520, Hodgdon CFE-223, IMR-4064 or Alliant Reloder 15. The low-residue formula provides ample port pressure to reliably cycle AR rifles. Charges filled cases fully, with 30.5 grains under 24- and 32-grain bullets reaching the top of the case neck. Match Rifle also produced the best results combined with Hornady’s 32-grain V-MAX, while shooting well under an inch with the NTX and a touch more than an inch with the 40-grain V-MAX – not too shabby for essentially random loads. Match Rifle seems the better choice for 40-grain bullets.