Posted by Faxon Firearms Staff on Feb 28th 2026
Best 6mm ARC Barrel Length: 12.5 vs 16 vs 20 vs 24 Explained
Best 6mm ARC Barrel Length: 12.5 vs 16 vs 20 vs 24
The 6mm ARC was designed to maximize ballistic efficiency inside the AR-15 platform. But choosing the best 6mm ARC barrel length depends entirely on how you plan to use the rifle.
Are you building a compact hunting rig? A do-everything rifle? Or a distance-focused precision setup?
• 12.5" – Compact, maneuverable, efficient
• 16" – Best all-around choice for most shooters
• 20" – Ideal balance of velocity and stability for distance
• 24" – Maximum velocity potential for dedicated precision builds
12.5" 6mm ARC Barrel – Compact & Efficient
A 12.5" barrel keeps the rifle extremely maneuverable while still delivering impressive performance thanks to the ARC’s high-BC projectiles.
- Short overall length
- Light front-end weight
- Great for compact or field rifles
- Excellent with modern 100–108gr factory loads
Estimated Velocity (108gr ELD-M): ~2460 FPS
Best Option: 15BARC75C12NGQ-5R-NP3 – Match Series Gunner 12.5"
16" 6mm ARC Barrel – The Best All-Around Choice
If someone asks, “What’s the best 6mm ARC barrel length?” the 16" mid-length configuration is the safest answer.
- Balanced velocity and handling
- Mid-length gas system
- Excellent for hunting and general purpose use
- Maintains AR-15 portability
Estimated Velocity (108gr ELD-M): ~2550 FPS
Best Option: 15BARC75M16NGQ-5R-NP3 – Match Series Gunner 16"
20" 6mm ARC Barrel – Distance-Ready
A 20" rifle-length system offers a noticeable velocity increase while maintaining practical rifle balance.
- Rifle-length gas for smoother pressure curve
- Improved retained energy at distance
- Excellent long-range hunting setup
- Available in Heavy Fluted or AXIS Target
Estimated Velocity (108gr ELD-M): ~2650 FPS
Match Series Heavy Fluted 20"
AXIS Series Target 20"
24" 6mm ARC Barrel – Maximum Velocity Potential
A 24" barrel is for shooters building a dedicated precision rig where velocity and stability are primary goals.
- Highest factory velocity potential
- Optimized for prone or bench setups
- Strong energy retention at extended distances
Hornady Official Velocity (108gr ELD-M 24" Test Barrel): 2750 FPS
Best Option: 15BARC75R24FHQ-5R-NP3 – Match Series Heavy Fluted 24"
Velocity Comparison (108gr ELD-M)
| Barrel Length | Estimated Muzzle Velocity | Use Case |
|---|---|---|
| 12.5" | ~2460 FPS | Compact builds |
| 16" | ~2550 FPS | All-purpose |
| 20" | ~2650 FPS | Distance-ready |
| 24" | 2750 FPS (Hornady test barrel) | Dedicated precision |
So… Which 6mm ARC Barrel Length Should You Choose?
- If you want maximum versatility → 16"
- If you want a compact rifle → 12.5"
- If you want long-range capability without going extreme → 20"
- If you’re building a dedicated precision rifle → 24"
Explore all available options here:
Shop All 6mm ARC Barrels