The pursuit of the absolute maximum performance from the AR platform has led to significant advancements in propellant technology, and at the center of this evolution stands Alliant AR-Comp. Originally developed as an advanced modification of the legendary Alliant Reloder 15, Alliant AR-Comp was engineered specifically to address the unique requirements of gas-operated semi-automatic rifles. Since its introduction, it has become a staple for competitive service rifle shooters and precision handloaders who require a propellant that delivers match-grade accuracy, high muzzle velocities, and unparalleled thermal stability.
Whether you are loading heavy 77-grain projectiles for a 223 Remington target rifle or developing a precision load for the 308 Winchester, Alliant AR-Comp provides the technical consistency needed for sub-MOA performance. This guide covers every aspect of this propellant, from its chemical architecture to its ideal component pairings.
Executive Summary
- Main Application: High-precision reloading for gas-operated semi-automatic rifles, specifically optimized for the AR-15 and AR-10 platforms.
- Key Advantage: Exceptional temperature stability and a pressure curve optimized for consistent port pressure.
- Burn Rate: Medium-fast rifle propellant, situated perfectly for heavy-bullet 223 Remington and match 308 Winchester.
- What This Guide Covers: In-depth technical profile, thermal stability metrics, 4-way market comparison, and comprehensive matching of primers and projectiles.
Best For: Competitive AR-15 shooters, PRS Gas Gun competitors, and hunters seeking high-consistency loads in medium-capacity rifle cartridges.
Powder Description & Technical Profile
Alliant AR-Comp is a single-base, extruded (stick) propellant that represents the next generation of the Reloder series. While its predecessor, Alliant Reloder 15, became famous as the powder for the military’s M118LR sniper ammunition, Alliant AR-Comp takes that baseline and refines it through advanced chemical engineering. The primary goal during the development of Alliant AR-Comp was to create a “Military Grade” propellant that could withstand extreme environmental shifts while maintaining the effortless metering required for high-volume reloading.
Physical Geometry
The grains of Alliant AR-Comp are manufactured with an ultra-consistent “short-cut” stick geometry. In the technical debate of spherical vs extruded powder, Alliant AR-Comp bridges the gap by offering the thermal stability of a stick powder with the metering fluidity often reserved for spherical types. The kernels are significantly shorter than those found in traditional powders like IMR 4064, allowing them to flow through mechanical measures with minimal “crunching” or bridging.
The Expert “Feel”
Reloaders often characterize Alliant AR-Comp by its “linear” pressure profile. In gas-operated rifles, the timing of the gas port is critical. Alliant AR-Comp provides a progressive push that ensures the bolt carrier group cycles reliably without the violent “over-gassed” impulse that can occur with slower-burning propellants. In the bore, Alliant AR-Comp leaves behind a very soft, grey carbon residue. This is the result of its high-purity nitrocellulose base and the omission of heavy deterrent coatings that can cause “gunk” buildup in the star chamber of an AR-15.
Pros & Cons
- Pros:
- World-class temperature stability across extreme heat and cold.
- Optimized for high-energy performance with heavy match bullets.
- Small grain size allows for exceptional metering in a Dillon XL-750.
- Very clean-burning, extending the time between deep cleanings of the gas system.
- Cons:
- Can be harder to find during market shortages due to high demand.
- Slightly lower bulk density may limit case fill in very small capacity cases.
Technical Characteristics
The technical profile of Alliant AR-Comp highlights its role as a specialized tool for the modern precision rifle reloader.
| Property | Specification |
| Manufacturer | Alliant Powder |
| Powder Type | Extruded (Short-Cut Stick) |
| Base | Single-Base |
| Density | 0.930 g/cc |
| Burn Rate Category | Medium-Fast Rifle |
| Coating | Technical Graphite and Thermal Stabilizers |
Temperature Stability & Burn Rate Analysis
The standout technical feature of Alliant AR-Comp is its temperature-insensitive formulation. While many propellants see muzzle velocity shifts of 1.5-2.0 FPS per degree of temperature change, Alliant AR-Comp drastically reduces this variance. This is achieved through a proprietary chemical additive package that regulates the burn rate even as the ambient temperature of the propellant rises or falls.
In technical field testing, Alliant AR-Comp typically exhibits velocity shifts of less than 0.5 FPS per degree Fahrenheit. For the tactical shooter or competitive marksman, this means that a load developed in a 55-degree environment will maintain its point of impact even when the mercury rises to 95 degrees on a summer range. This “flat” response eliminates the need for complex density altitude adjustments for the powder itself, allowing the shooter to focus entirely on wind and atmospheric variables.
Stability Benchmark Comparison
| Powder Name | Stability Level | Tech Category |
| Alliant AR-Comp | World-Class | Insensitive Extruded |
| Hodgdon Varget | Extreme | Insensitive Extruded |
| Alliant Reloder 15 | Standard | Double-Base Extruded |
| Accurate 2520 | Moderate | Double-Base Spherical |
Powder Comparison
To understand where Alliant AR-Comp sits in the current market, it must be compared to its most frequent competitors in the medium-burn range.
- Hodgdon Varget: The primary accuracy rival. While Varget is the gold standard for temperature insensitivity, Alliant AR-Comp features smaller grains that meter significantly better in volumetric measures and often yields higher velocities in the 223 Remington.
- IMR 8208 XBR: A very close burn-rate competitor. Both are “short-cut” powders designed for stability. 8208 XBR is often preferred for 55-62 grain bullets, whereas Alliant AR-Comp typically provides the “edge” for 69-80 grain projectiles.
- Hodgdon CFE 223: A spherical alternative. CFE 223 offers higher top-end velocities and copper-erasing technology, but it lacks the extreme thermal stability found in Alliant AR-Comp.
- Accurate 2520: The “Camp Perry” powder. While 2520 is a legendary service rifle propellant, it is a double-base ball powder that is much more sensitive to temperature swings than Alliant AR-Comp.
Competitor Comparison Table
| Powder | Burn Rate | Density (g/cc) | Primary Cartridges |
| Alliant AR-Comp | Medium-Fast | 0.930 | 223 Remington, 308 Winchester |
| Hodgdon Varget | Medium | 0.885 | 308 Winchester, 6.5 Creedmoor |
| IMR 8208 XBR | Medium-Fast | 0.915 | 223 Remington, 6mm ARC |
| Hodgdon CFE 223 | Medium | 0.970 | 223 Remington, 224 Valkyrie |
| Alliant Reloder 15 | Medium | 0.925 | 308 Winchester, 303 British |
Performance, Metering & Equipment
Metering Consistency
One of the most praised aspects of Alliant AR-Comp is its ability to be dropped through volumetric measures with extreme precision. In a high-quality measure like the RCBS Uniflow Powder Measure 3, reloaders can expect charge variances of less than 0.1 grains. For those utilizing progressive presses for high-volume service rifle match loads, this allows for match-grade consistency without the need to hand-weigh every single charge.
Fouling and Cleanliness
Alliant AR-Comp is an exceptionally clean-burning propellant. Because it was designed for the AR platform, the chemical engineers at Alliant focused on ensuring that combustion byproduct does not interfere with the gas system. This is a critical technical advantage for shooters who engage in long-format competitions where firing 80-100 rounds without cleaning is mandatory. The reduction in carbon buildup also helps preserve the life of the bolt carrier group’s gas rings and minimizes the “carbon ring” that can form in the barrel’s throat.
Recommended Cartridges and Applications
While optimized for the AR platform, the versatility of Alliant AR-Comp allows it to perform at an elite level in a variety of standard and short-action cartridges.
| Cartridge | Primary Application |
| 223 Remington | Match loads with 69-80 grain bullets |
| 308 Winchester | Precision loads with 150-168 grain bullets |
| 6.5 Grendel | Optimal case fill for 100-123 grain bullets |
| 6mm ARC | High-velocity match accuracy |
| 224 Valkyrie | Consistent performance with 75-80 grain bullets |
| 243 Winchester | Efficient hunting loads with light-to-midweight bullets |
| 204 Ruger | Maximum velocity for varmint hunting |
Bullets
To leverage the high-energy and stability of Alliant AR-Comp, pairing it with projectiles that offer a high ballistic coefficient for their weight class is essential.
| Bullet Brand/Model | Recommended Weight | Application |
| Sierra MatchKing | 77 grain (223) / 168 grain (308) | Service Rifle Match |
| Hornady ELD Match | 73-75 grain (223) | Long-Range Precision |
| Nosler AccuBond | 150 grain (308) | Big Game Hunting |
| Berger VLD Target | 80 grain (223) | Single-Feed 600 Yard Match |
| Sierra Tipped GameKing | 165 grain (308) | Modern Hunting |
| Hornady V-Max | 53-55 grain (223) | High-Velocity Varminting |
Primers
Consistent ignition is the final technical hurdle for achieving low velocity spreads. Alliant AR-Comp responds exceptionally well to high-quality primers that provide a uniform spark.
- CCI 41: The military-spec small rifle primer. Essential for prevent slam-fires in semi-auto 223 Remington rifles.
- Federal GM205MAR: A match-grade primer designed specifically for the higher firing pin energy of AR-platform rifles.
- CCI BR-4: Benchrest quality small rifle primer for the absolute lowest standard deviations.
- Winchester WSR: Provides a consistent, hot spark that ensures efficient ignition of Alliant AR-Comp.
- Federal GM210M: The gold standard for match accuracy in 308 Winchester.
- CCI 34: The military large rifle primer, necessary for AR-10 or M1A platforms to ensure safety.
- Remington 7-1-2: A durable small rifle primer suitable for high-pressure precision loads.
- RWS 4033: Premium European primer for elite small-bore match performance.
- Fiocchi Small Rifle Magnum: Excellent for ensuring consistent ignition in sub-zero winter conditions.
Expert Verdict
Alliant AR-Comp is more than just a powder; it is a specialized technical solution for the most demanding shooters in the world. Its ability to combine world-class thermal stability with effortless metering and match-grade accuracy has solidified its place as one of the most respected propellants on the market today. While other powders may offer higher raw velocities, few can match the shot-to-shot consistency and reliability of Alliant AR-Comp across the massive spectrum of environmental conditions.
If you are developing a load for a precision 223 Remington or a long-range 308 Winchester, Alliant AR-Comp should be the very first propellant you test in your load development process.
Expert Pro Tip: When developing loads with Alliant AR-Comp for an AR-15, focus on achieving a high case fill (typically 92-96%). This propellant performs its absolute best when it is filling the case efficiently. To ensure absolute uniformity, use a Frankford Arsenal Powder Trickler to find your initial accuracy node, then utilize a Dillon XL-750 or similar progressive press for bulk production. The small grain size of Alliant AR-Comp will ensure that your volumetric drops remain identical round-after-round, resulting in the single-digit Standard Deviations required for long-range success.
