Historical Background

The lineage of Windham Weaponry is deeply rooted in American firearm manufacturing heritage, bringing together a veteran team of gunsmiths and craftsmen dedicated to producing duty-grade direct impingement firearms. Combining classic, battle-proven design with modern, high-precision manufacturing, Windham Weaponry pays tribute to iconic retro platforms while delivering uncompromised operational reliability.

Within Windham Weaponry’s lineup, the A1 Government and A4 Government Series were developed as modern retro builds that honor American military service rifle heritage; from the Vietnam-era M16A1 to the global-war-on-terror era M16A4; while integrating modern metallurgic standards and precise barrel specifications for collector-grade durability and performance.

Technical Overview

Both the Windham Weaponry A1 Government and A4 Government utilize full-length direct gas impingement operating systems chambered in .223 Remington / 5.56mm NATO. Built around traditional 20-inch rifle profile barrels, both platforms maximize muzzle velocity, reduce felt recoil, and deliver long-range ballistic performance inherent to full-length rifle gas systems.

Construction & Receivers

• Upper & Lower Receivers: Constructed from high-grade forged 7075 T6 aircraft aluminum and finished with a durable black hardcoat anodize.

  • A1 Government Upper: Features a fixed A1 carry handle with integrated dual-aperture rear sight, built-in brass deflector, and classic teardrop forward assist.

  • A4 Government Upper: Features a modern flat-top upper with a removable A4 carry handle mounted to a Picatinny rail, allowing instant conversion to magnified optics or red dot sights. Includes a standard round forward assist.

• Barrels & Metallurgy: The 20-inch barrels are machined from heavy-duty 4150 Chrome Moly Vanadium steel with M4 feed ramps. Both feature fully chrome-lined bores and chambers for extreme heat resistance and longevity under sustained fire. Cut with a fast 1:7 (RH) twist rate, both models accurately stabilize heavier modern projectiles (62gr to 77gr) alongside standard 55gr ammunition.

  • A1 Profile: Styled with a classic lightweight profile tapering ahead of the sight base.

  • A4 Profile: Configured in a government profile (thinner under the handguard, heavier ahead of the sight base).

• Bolt Assemblies: Precision-machined from high-strength Carpenter 158 steel to ensure maximum heat resistance and structural integrity under heavy firing schedules.

Furniture & Ergonomics

• Handguards:

  • A1 Government: Outfitted with classic rifle-length triangular handguards fitted with an A1 delta ring.

  • A4 Government: Outfitted with rifle-length M16A2/A4 round rib-pattern handguards fitted with an A2 tapered retaining ring.

• Controls & Furniture:

  • A1 Government: Equipped with an A1-style pistol grip and an A2 solid fixed stock with a trapdoor storage compartment.

  • A4 Government: Outfitted with a standard A2 pistol grip (finger groove) and an A2 solid fixed buttstock with a trapdoor storage compartment.

• Muzzle Devices & Sights:

  • A1 Government: Fitted with an A1-style birdcage flash suppressor, A1 windage-adjustable rear aperture in the fixed carry handle, and a square post A2 front sight base.

  • A4 Government: Fitted with a standard A2 flash hider, fully adjustable A4 rear sight (windage and elevation) housed within the removable carry handle, and an F-marked square post front sight base.