Barrel length has a major impact on the performance, handling, and legal classification of your AR-15. Whether you're building a compact AR pistol or a precision rifle, knowing the trade-offs of each length is key. Below is a breakdown of 5.56 barrels ranging from 5” all the way to 24”.
5" to 7.5" Barrels – Ultra-Compact Configurations
These extremely short barrels are usually found on specialty AR pistols. They offer maximum compactness, but drastically reduce velocity and ballistic efficiency. Commonly used for close-quarters setups or suppressed builds.
Best For:
Considerations:
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Poor terminal performance past short distances
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Loud, with significant flash and concussion
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May cause cycling issues without tuned components
8" to 10.5" Barrels – Tactical Short-Barrel Builds
This range hits a sweet spot for tactical-style AR pistols and SBRs. Popular for maneuverability and acceptable performance at close to moderate ranges.
Best For:
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CQB
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Home defense
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Suppressed setups
11.5" to 13.7" Barrels – Mid-Length Compact
These barrel lengths are a solid choice for tactical users wanting more velocity than a 10.5" without the legal restrictions of a 14.5". The 13.7" especially has become popular when paired with a pinned muzzle device.
Best For:
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Tactical or defensive carbine builds
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Shooters wanting maneuverability with added range
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Non-NFA configurations (when pinned/welded)
14.5" Barrels – Military Standard
A classic length used on M4 carbines. Offers a solid balance of range, weight, and performance, but must be pinned and welded to meet the 16" legal minimum for rifles.
16" Barrels – Civilian Gold Standard
The most common length for non-NFA AR-15 rifles. Delivers optimal velocity and reliability, making it an excellent all-around option.
Best For:
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General-purpose builds
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Target shooting, hunting, and defense
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Legal compliance without extra paperwork
18" to 20" Barrels – Precision and Distance
These longer barrels are often used in designated marksman rifles (DMR) or varmint hunting rifles. They offer superior velocity and accuracy at extended ranges.
Best For:
22" to 24" Barrels – Maximum Velocity and Range
These lengths are rarely used on AR-15s but can be found in specialty setups where maximum velocity and long-range precision are the goal. Typically heavier and more cumbersome.
Best For:
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Long-range bench shooting
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Competition or precision builds
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Reloaders optimizing ballistic performance
Conclusion
From ultra-short 5” barrels to full-length 24” precision setups, your choice depends on application. If you need compact mobility, stay below 11”. For general use, 14.5” or 16” is ideal. For precision or hunting, go long.
No matter your choice, Moriarti Armaments offers a full lineup of AR-15 uppers and barrels designed for every shooting style. Build with confidence and performance in mind.
