GAU-5A COMPLETE UPPER RECEIVER & 4X RETRO CARRY HANDLE SCOPE – BRN GAU-5A 5.56MM 12.7” BBL 1-12 TWIST W/COLT 4X21MM SCOPE

Specifications

  • Cartridge: 5.56 x 45
  • Muzzle: 1/2-28
  • Length: 12.7''
  • Contour: Lightweight
  • Make: AR-15
  • Color: Black
  • Twist: 1-12
  • Style: Complete

GAU-5A 12.7"" 1-12 UPPER RECEIVER

Based on the unique early carbine configurations, these GAU-5A Upper Receivers are ready for your next Retro build.

The muzzle of the GAU-5A Upper Receiver, is capped by the classic XM177/GAU-5 moderator inspired flash hider, with ports around its radius. This muzzle device is a flash hider, unlike the original XM177 muzzle device, which was technically a suppressor.

The flash hider is attached to a lightweight 11.5 or 12.7 inch barrel. Why 12.7 inch? The 12.7 inch model has its muzzle device pinned and welded in place, allowing the overall length of the barrel to reach the required 16” for a rifle.

Uppers are available with a 1-12 twist barrel The front sight base is not F-marked, meaning the round, tapered front sight post is properly in line with the carry handle rear sight. The black carbine handguards closely emulate the original CAR handguards. These barrel assemblies do have a tapered slip ring, which is proper on early carbines of this type.

Mounted to the upper is a proper ejection port cover, with a flat external ""bump"" (not just an off the shelf A2). The receiver is the proper M16 slick side style, without a forward assist but no shell deflector. The rear sight is the standard A1 aperture, that can easily be adjusted with a cartridge or tool. Included bolt carrier group is the proper manganese phosphate mil-spec BCG, with chrome lined interior.

KEY FEATURES OF THE GAU-5A COMPLETE UPPER RECEIVERS:

  • M16 slick side upper receiver without shell deflector or forward assist
  • XM177 flash hider with proper grenade ring
  • 11.5” or 12.7” 5.56x45mm NATO barrel
  • 12.7” configuration features a NOT pinned or welded muzzle device, OR comes with a pinned and welded muzzle device–making it 16”+
  • 1-12 twist & chrome bore & chamber
  • M16A1 ejection port cover
  • A1 rear sight assembly
  • Carbine black polymer handguards with heatshields
  • Manganese phosphate mil-spec bolt carrier group with 9310 bolt

AR-15/M16 4X RETRO CARRY HANDLE SCOPE

  • We actually tracked down the original company that manufactured the Colt® AR-15 optics of the 1970s and asked them to build a new one for us as close to the original as possible – right down the yellow inspection stickers. The Retro 4x Optic has updated technology under the hood, with modern lenses and construction. The result is a scope that looks just like the original but has optical clarity and performance that are head and shoulders above it.

FEATURES

  • Attaches to any standard AR-15/M16 carry handle
  • Fully Multicoated lenses are fog and waterproof
  • BDC click-adjustable elevation turret
  • Manufactured in Japan with high quality internals and lenses
  • The Retro 4x Carry Handle Optic sports a simple, intuitive fine duplex reticle, like the original, and an elevation turret with BDC (ballistic drop compensated) clicks that closely match modern .223/5.56 55gr and 62gr ammo. As its name indicates, the Retro 4x comes with an integral carry handle mount that easily attaches to most AR-15 carry handles – no tools required.
  • As with all products we sell, this scope is fully backed by our Forever Guarantee.
Description

Original price was: $977.99.Current price is: $738.47.

GAU-5A 12.7"" 1-12 UPPER RECEIVER

Based on the unique early carbine configurations, these GAU-5A Upper Receivers are ready for your next Retro build.

The muzzle of the GAU-5A Upper Receiver, is capped by the classic XM177/GAU-5 moderator inspired flash hider, with ports around its radius. This muzzle device is a flash hider, unlike the original XM177 muzzle device, which was technically a suppressor.

The flash hider is attached to a lightweight 11.5 or 12.7 inch barrel. Why 12.7 inch? The 12.7 inch model has its muzzle device pinned and welded in place, allowing the overall length of the barrel to reach the required 16” for a rifle.

Uppers are available with a 1-12 twist barrel The front sight base is not F-marked, meaning the round, tapered front sight post is properly in line with the carry handle rear sight. The black carbine handguards closely emulate the original CAR handguards. These barrel assemblies do have a tapered slip ring, which is proper on early carbines of this type.

Mounted to the upper is a proper ejection port cover, with a flat external ""bump"" (not just an off the shelf A2). The receiver is the proper M16 slick side style, without a forward assist but no shell deflector. The rear sight is the standard A1 aperture, that can easily be adjusted with a cartridge or tool. Included bolt carrier group is the proper manganese phosphate mil-spec BCG, with chrome lined interior.

KEY FEATURES OF THE GAU-5A COMPLETE UPPER RECEIVERS:

  • M16 slick side upper receiver without shell deflector or forward assist
  • XM177 flash hider with proper grenade ring
  • 11.5” or 12.7” 5.56x45mm NATO barrel
  • 12.7” configuration features a NOT pinned or welded muzzle device, OR comes with a pinned and welded muzzle device–making it 16”+
  • 1-12 twist & chrome bore & chamber
  • M16A1 ejection port cover
  • A1 rear sight assembly
  • Carbine black polymer handguards with heatshields
  • Manganese phosphate mil-spec bolt carrier group with 9310 bolt

AR-15/M16 4X RETRO CARRY HANDLE SCOPE

  • We actually tracked down the original company that manufactured the Colt® AR-15 optics of the 1970s and asked them to build a new one for us as close to the original as possible – right down the yellow inspection stickers. The Retro 4x Optic has updated technology under the hood, with modern lenses and construction. The result is a scope that looks just like the original but has optical clarity and performance that are head and shoulders above it.

FEATURES

  • Attaches to any standard AR-15/M16 carry handle
  • Fully Multicoated lenses are fog and waterproof
  • BDC click-adjustable elevation turret
  • Manufactured in Japan with high quality internals and lenses
  • The Retro 4x Carry Handle Optic sports a simple, intuitive fine duplex reticle, like the original, and an elevation turret with BDC (ballistic drop compensated) clicks that closely match modern .223/5.56 55gr and 62gr ammo. As its name indicates, the Retro 4x comes with an integral carry handle mount that easily attaches to most AR-15 carry handles – no tools required.
  • As with all products we sell, this scope is fully backed by our Forever Guarantee.

66 in stock

SKU 430111109 Category

Description

GAU-5A 12.7"" 1-12 UPPER RECEIVER

Based on the unique early carbine configurations, these GAU-5A Upper Receivers are ready for your next Retro build.

The muzzle of the GAU-5A Upper Receiver, is capped by the classic XM177/GAU-5 moderator inspired flash hider, with ports around its radius. This muzzle device is a flash hider, unlike the original XM177 muzzle device, which was technically a suppressor.

The flash hider is attached to a lightweight 11.5 or 12.7 inch barrel. Why 12.7 inch? The 12.7 inch model has its muzzle device pinned and welded in place, allowing the overall length of the barrel to reach the required 16” for a rifle.

Uppers are available with a 1-12 twist barrel The front sight base is not F-marked, meaning the round, tapered front sight post is properly in line with the carry handle rear sight. The black carbine handguards closely emulate the original CAR handguards. These barrel assemblies do have a tapered slip ring, which is proper on early carbines of this type.

Mounted to the upper is a proper ejection port cover, with a flat external ""bump"" (not just an off the shelf A2). The receiver is the proper M16 slick side style, without a forward assist but no shell deflector. The rear sight is the standard A1 aperture, that can easily be adjusted with a cartridge or tool. Included bolt carrier group is the proper manganese phosphate mil-spec BCG, with chrome lined interior.

KEY FEATURES OF THE GAU-5A COMPLETE UPPER RECEIVERS:

  • M16 slick side upper receiver without shell deflector or forward assist
  • XM177 flash hider with proper grenade ring
  • 11.5” or 12.7” 5.56x45mm NATO barrel
  • 12.7” configuration features a NOT pinned or welded muzzle device, OR comes with a pinned and welded muzzle device–making it 16”+
  • 1-12 twist & chrome bore & chamber
  • M16A1 ejection port cover
  • A1 rear sight assembly
  • Carbine black polymer handguards with heatshields
  • Manganese phosphate mil-spec bolt carrier group with 9310 bolt

AR-15/M16 4X RETRO CARRY HANDLE SCOPE

  • We actually tracked down the original company that manufactured the Colt® AR-15 optics of the 1970s and asked them to build a new one for us as close to the original as possible – right down the yellow inspection stickers. The Retro 4x Optic has updated technology under the hood, with modern lenses and construction. The result is a scope that looks just like the original but has optical clarity and performance that are head and shoulders above it.

FEATURES

  • Attaches to any standard AR-15/M16 carry handle
  • Fully Multicoated lenses are fog and waterproof
  • BDC click-adjustable elevation turret
  • Manufactured in Japan with high quality internals and lenses
  • The Retro 4x Carry Handle Optic sports a simple, intuitive fine duplex reticle, like the original, and an elevation turret with BDC (ballistic drop compensated) clicks that closely match modern .223/5.56 55gr and 62gr ammo. As its name indicates, the Retro 4x comes with an integral carry handle mount that easily attaches to most AR-15 carry handles – no tools required.
  • As with all products we sell, this scope is fully backed by our Forever Guarantee.

Additional information

Muzzle

1/2-28

Length

12.7''

Cartridge

AKK_5.56 x 45

Contour

Lightweight

Make

AR-15

Color

Black

Twist

1-12

Style

Complete

Make/Model

AR-15

Frequently Asked Questions

Are these brass cases and reloading components factory-new or once-fired? +

We stock both premium factory-new components and high-quality once-fired brass. Please check the specific product listing title and description carefully; once-fired brass is fully inspected, but we always recommend resizing and inspecting prior to priming and powder charging.

Will this case trimmer gauge or die set work with my progressive press setup? +

Our standard reloading dies and case length trimmer accessories utilize industry-standard threads (typically 7/8"-14) compatible with major single-stage, turret, and progressive presses like RCBS, Hornady, Lee Precision, and Dillon. Caliber-specific trim gauges must match your exact brass caliber.

Do you enforce shipping restrictions on powder, primers, or live ammunition? +

Yes. Non-hazardous reloading equipment (dies, case length trimmers, gauges, and unprimed brass) ships via standard ground carriers with no extra fees. Any orders containing smokeless powders or primers will incur standard federal HazMat handling fees and cannot be shipped via air transportation.

How can I track my shipment to ensure delivery safety? +

Precision reloading gear is valuable, so all orders are shipped with tracking enabled. As soon as your package is dispatched from our inventory warehouse, a tracking number will be emailed to you. You can monitor your shipment directly on our Track Order page using your unique Order ID.

Can I return precision measuring tools or die components if they don’t fit? +

We accept returns on unused, unaltered tools, case preparation equipment, and unopened component boxes within 30 days of item delivery. Due to safety and strict quality control on the reloading bench, we absolutely cannot accept returns on opened packs of primers, smokeless powder, or processed brass casings.