The PWS MK110 Alpha SBR is a limited-production 5.56 NATO short-barreled rifle with a 10.5-inch barrel, built by Primary Weapons Systems around its long-stroke piston system (brand part no. MK1ALPHA55610NFA). Only 150 are being produced, each individually numbered, and PWS says this configuration will not be made again. The receivers and ALPHA handguard wear a green anodized finish matched to ODG Magpul MOE SL-S and K2 furniture, and the rifle comes with a Geissele SD-E trigger, a Radian Raptor ambidextrous charging handle, an A5 buffer system and a Magpul 30-round PMAG. It is a premium piston SBR for a collector who still intends to shoot it.

Key Specifications

• The chambering is 5.56x45mm NATO, with a chamber PWS designed around mid- to heavy-grain 5.56 ammunition.
• Barrel length is 10.5 inches, compact enough for a vehicle or a hallway while keeping usable velocity.
• The rate of twist is 1:7, which stabilizes the average to heavier bullet weights a short 5.56 barrel favors.
• The operating system is the PWS long-stroke piston with adjustable gas settings, known for reliability and reduced fouling.
• Weight is 6.0 pounds unloaded for the complete rifle, per PWS.

Frequently Asked Questions

Is the MK110 Alpha set up for a suppressor? Yes. PWS calls it suppressor optimized, with adjustable gas that minimizes back pressure, and its FRC 2-Port Compensator works with the PWS PUB suppressor mount used by the Rearden Atlas and Q Plan B systems.

Do I need ATF approval to buy this? No. As of October 9, 2026, ATF no longer requires Form 4 approval, registration or a tax stamp for short-barreled rifles. It transfers on a Form 4473 with a background check through a Class 3 (SOT) dealer. State and local laws still apply. Taking an SBR across state lines still requires an approved ATF Form 5320.20.

Buy the PWS MK110 Alpha SBR, 5.56 NATO, 10.5-Inch, ODG

As of October 9, 2026, this short-barreled rifle transfers on a Form 4473 with a background check at your Class 3 (SOT) dealer, with no Form 4 or tax stamp; state and local laws still apply. Order through Primary Weapons Systems‘s short-barreled rifles lineup and our Lubbock, Texas team will handle the transfer, and it ships fast to your Class 3 dealer.