5.56mm Build Kits
At Grid Defense, we offer a wide selection of 5.56mm AR-15 build kits to help you create the perfect custom rifle. Our 7.5", 10.5" and 16" include the parts you need to build a high-quality, reliable rifle, including barrels, handguards, stocks, and more. These kits do not include a lower receiver.
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Grid Defense 16" 5.56 Rifle Kit with Magpul Accessories - Black
$717.90Grid Defense 16" 5.56 Upper Receiver - Black Premium AR upper receiver, the new 5.56 AR upper from Grid Defense.With hard coat black anodized. Chambered in 5.56x45 NATO Skeletonized Upper Receivers 14" M-Lok Rail 16" 1:7 4150 M4 Barrel - Black...$717.90 -
On Sale
Ghost 10.5" American Flag Engraved Upper 5.56 Pistol Kit - Black
Sale: $419.00MSRP: $494.00Ghost 10.5" American Flag Engraved Upper 5.56 Pistol Kit - Black Chambered in 5.56x45 NATO (5.56/.223) A2 Birdcage Flash Hider 10.5" 1:7 Twist 4150 M4 Barrel Black Nitride Carbine Length Gas System Ghost Firearms 9" M-Lok Free...Sale: $419.00MSRP: $494.00 -
Out of stockOn Sale
ALWAYS ARMED JESTER 16" 5.56 NATO RIFLE KIT - BLACK
Sale: $349.00MSRP: $469.00Always Armed Jester 16" 5.56 NATO Rifle Kit - Black Anodized Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 16" 1:7 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Carbine Length Gas System ...Sale: $349.00MSRP: $469.00 -
On Sale
ALWAYS ARMED Jester 10.5" 5.56 NATO JESTER FLASH CAN PISTOL KIT - BLACK
Sale: $359.00MSRP: $509.00Always Armed 10.5" 5.56 NATO Jester Pistol Kit - Black Anodized Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 10.5" 1:7 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Carbine Length Gas...Sale: $359.00MSRP: $509.00 -
GHOST FIREARMS 16" 5.56 WITH 14" M-LOK RAIL RIFLE KIT WITH MOE STOCK AND MOE+ GRIP- BLACK
$662.90GHOST FIREARMS 16" 5.56 RIFLE KIT Hard Coat Black Anodized Chambered in 5.56 NATO 16" 1:7 Twist 4150 M4 Black Nitride Barrel 14" Ghost Firearms Free Float M-LOK Rail A2 Muzzle Device Mil-Spec 7075-T6 Upper Receiver Mil-Spec Lower Parts...$662.90 -
On Sale
ALWAYS ARMED OCTO SERIES 16" 5.56 NATO RIFLE KIT - BLACK
Sale: $349.00MSRP: $469.00ALWAYS ARMED OCTO SERIES 16" 5.56 NATO RIFLE KIT Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 16" 1:7 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Carbine Length Gas System .750 Low...Sale: $349.00MSRP: $469.00 -
On Sale
ALWAYS ARMED 10.5" 5.56 NATO BX SERIES PISTOL KIT - BLACK ANODIZED
Sale: $349.00MSRP: $479.00ALWAYS ARMED 10.5" 5.56 NATO BX SERIES PISTOL KIT Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 10.5" 1:7 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Carbine Length Gas System .750 Low...Sale: $349.00MSRP: $479.00 -
On Sale
ALWAYS ARMED 16" 5.56 NATO TRX RIFLE KIT - BLACK
Sale: $349.00MSRP: $469.00ALWAYS ARMED 16" 5.56 NATO TRX RIFLE KIT Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 16" 1:7 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Carbine Length Gas System .750 Low Profile Gas...Sale: $349.00MSRP: $469.00 -
On Sale
ALWAYS ARMED 7.5" 5.56 NATO PISTOL KIT - BLACK
Sale: $339.00MSRP: $459.00Always Armed 7.5" 5.56 NATO Pistol Kit - Black Anodized Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 7.5" 1:7 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Pistol Length Gas System .750...Sale: $339.00MSRP: $459.00 -
On Sale
ALWAYS ARMED 7.5" 5.56 NATO PISTOL KIT - MAGPUL FDE
Sale: $359.00MSRP: $499.00Always Armed 7.5" 5.56 NATO Pistol Kit - Magpul FDE Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 7.5" 1:7 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Pistol Length Gas System .750 Low...Sale: $359.00MSRP: $499.00 -
On Sale
ALWAYS ARMED 10.5" 5.56 NATO PISTOL KIT - BLACK ANODIZED
Sale: $339.00MSRP: $479.00Always Armed 10.5" 5.56 NATO Pistol Kit - Black Anodized Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 10.5" 1:7 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Carbine Length Gas System .750...Sale: $339.00MSRP: $479.00 -
On Sale
ALWAYS ARMED 10.5" 5.56 NATO PISTOL KIT - MAGPUL FDE
Sale: $359.00MSRP: $499.00Always Armed 10.5" 5.56 NATO Pistol Kit - Magpul FDE Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 10.5" 1:7 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Carbine Length Gas System .750 Low...Sale: $359.00MSRP: $499.00 -
On Sale
ALWAYS ARMED 16" 5.56 NATO RIFLE KIT - BLACK
Sale: $349.00MSRP: $529.00Always Armed 16" 5.56 NATO Rifle Kit - Black Anodized Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 16" 1:7 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Carbine Length Gas System ...Sale: $349.00MSRP: $529.00 -
On Sale
ALWAYS ARMED 16" 5.56 NATO RIFLE KIT - SIG PINK
Sale: $379.00MSRP: $529.00Always Armed 16" 5.56 NATO Rifle Kit - Sig Pink Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 16" 1:7 or 1:8 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Carbine Length Gas System ...Sale: $379.00MSRP: $529.00 -
On Sale
ALWAYS ARMED 16" 5.56 NATO RIFLE KIT - BURNT BRONZE
Sale: $379.00MSRP: $529.00Always Armed 16" 5.56 NATO Rifle Kit - Burnt Bronze Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 16" 1:7 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Carbine Length Gas System .750...Sale: $379.00MSRP: $529.00 -
On Sale
ALWAYS ARMED 16" 5.56 NATO RIFLE KIT - MAGPUL FDE
Sale: $379.00MSRP: $529.00Always Armed 16" 5.56 NATO Rifle Kit - Magpul FDE Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 16" 1:7 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Carbine Length Gas System .750...Sale: $379.00MSRP: $529.00 -
On Sale
ALWAYS ARMED 16" 5.56 NATO RIFLE KIT - TITANIUM
Sale: $379.00MSRP: $529.00Always Armed 16" 5.56 NATO Rifle Kit - Titanium Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 16" 1:7 or 1:8 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Carbine Length Gas System ...Sale: $379.00MSRP: $529.00 -
On Sale
ALWAYS ARMED 16" 5.56 NATO RIFLE KIT - BAZOOKA GREEN
Sale: $379.00MSRP: $529.00Always Armed 16" 5.56 NATO Rifle Kit - Bazooka Green Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 16" 1:7 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Carbine Length Gas System .750...Sale: $379.00MSRP: $529.00 -
On Sale
ALWAYS ARMED 16" 5.56 NATO RIFLE KIT - SMITH & WESSON RED
Sale: $379.00MSRP: $529.00Always Armed 16" 5.56 NATO Rifle Kit -Smith & Wesson Red Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 16" 1:7 or 1:8 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Carbine Length...Sale: $379.00MSRP: $529.00 -
On Sale
ALWAYS ARMED 16" 5.56 NATO RIFLE KIT - RIDGEWAY BLUE
Sale: $379.00MSRP: $529.00Always Armed 16" 5.56 NATO Rifle Kit - Ridgeway Blue Made in the USA Mil-Spec 7075 T6 Upper Receiver with Dust Cover and Forward Assist 16" 1:7 or 1:8 Twist 4150 Barrel with Black Nitride Finish Chambered in 5.56 NATO Carbine Length Gas System ...Sale: $379.00MSRP: $529.00