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FN 15 Guardian 5.56 NATO
5.56 NATO • FN America

FN 15 Guardian 5.56 NATO

Model: 36-100740

30
CAPACITY
16.0"
BARREL
6.6
LBS
Semi-Auto
ACTION
5.56 NATO
CALIBER
$999
MSRP

Full Specifications

Series Guardian
Action Type Semi-Auto
Trigger Mil-Spec Single Stage
Safety Mil-Spec Safety Selector
Optic Ready Yes
Magazines Included 1
Overall Length 35.5"
Barrel Length 16.0"
Weight 105.6 oz (6.6 lbs)
Frame Material Aluminum
Receiver Material 7075-T6 Aluminum
Receiver Finish Hard Coat Anodized
Barrel Material 4150 Chrome Moly Vanadium Steel
Barrel Finish Nitride
Twist Rate 1:7"
Thread Pattern 1/2x28
Muzzle Device A2 Flash Hider
Bolt Material 9310 Steel
Stock Material Polymer
Grip Type Ergonomic FN Pistol Grip
Country of Origin USA

About This Firearm

The FN 15 Guardian is FN America's entry-level AR-15, built on the same Columbia, SC manufacturing line that produces their military contract rifles. The 16-inch barrel uses 4150 chrome moly vanadium steel with a nitride finish and 1:7 twist, paired with a 9310 steel bolt carrier group. The 7075-T6 aluminum receivers get a hard coat anodized finish. At 105.6 oz (6.6 lbs), it runs heavier than most rifles in FN's own lineup, partly due to the standard-profile barrel.

FN ships the Guardian with a 6-position collapsible stock, M-LOK and Picatinny rail compatibility, and a standard A2 flash hider. No iron sights are included, so budget for optics and backup sights from the start. The mil-spec single-stage trigger and standard safety selector keep things simple, and the 30-round magazine is a single Magpul PMAG.

Best For

GOOD
Range / Training
The 4150 CMV nitride barrel handles high round counts well, and the 1:7 twist stabilizes the heavier 62-77gr training loads that many ranges stock. The 105.6 oz weight adds stability off a bench. The mil-spec trigger is predictable even if it is not refined.
FAIR
Home Defense
The A2 flash hider keeps muzzle flash manageable in low light. At 35.5 inches overall with the stock extended, it is a standard-length carbine. The lack of factory sights means you need to mount an optic or irons before the rifle is ready for duty, which adds setup time and cost.

Strengths & Limitations

Strengths
  • Built on FN's military production line with a 4150 CMV nitride barrel and 9310 steel bolt, giving it the same base metallurgy as their contract rifles
  • The M-LOK and Picatinny rail system accepts most aftermarket handguards, lights, and grips without adapter plates
  • Straightforward mil-spec controls make it easy for new AR owners to find compatible parts and accessories
Limitations
  • At 105.6 oz (6.6 lbs), it is noticeably heavier than the FN 15 SRP G2 at 100 oz and the SAINT Edge at 99 oz
  • No iron sights are included, so the rifle is not functional out of the box without purchasing an optic or sight set separately

Category Rankings

How the FN 15 Guardian 5.56 NATO ranks among full-size 5.56 NATO rifles.

Capacity
#3 of 25
Top 12%
30 rds
Weight
#13 of 25
Top 52%
6.6 lbs
Barrel
#8 of 25
Top 32%
16.0"
MSRP
#8 of 25
Top 32%
$999
Overall Length
#8 of 25
Top 32%
35.5"

Compatible Ammunition

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Where to Buy

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Frequently Asked Questions

How does the FN 15 Guardian compare to the FN 15 SRP G2?

The Guardian is FN's entry-level model with a standard-profile nitride barrel, mil-spec trigger, and no iron sights. The SRP G2 adds a manganese phosphate barrel finish, folding metal sights, an A2 compensator, and is 5.6 oz lighter at 100 oz. The SRP G2 also has a higher trigger pull weight at 6.3 lbs, but the overall parts selection leans more toward duty use.

What optic mount system does the Guardian use?

The flat-top upper receiver has a standard Picatinny rail that accepts any MIL-STD-1913 optic mount. This covers virtually every red dot, LPVO, and magnified scope mount on the market. The M-LOK handguard slots accept Picatinny rail sections for mounting a front sight, laser, or light at various positions along the forend.