Military Arms Mac 5K 9MM 301 5 80IN Threaded Barrel

About this product

The Military Armament Corp MAC-5K is a modern, semi-automatic reproduction of the MP5K-style roller-delayed blowback platform, chambered in 9mm with a 5.8-inch threaded barrel. Note on pricing: the manufacturer's own site currently lists this model at $1,329.00, while this listing's $949 price may reflect an earlier promotional price point — the specs below are confirmed from Military Armament Corp's official product page regardless of price.

What does "roller-delayed" mean, and why does it matter?

Roller-delayed blowback is the same operating system made famous by H&K's MP5 line — rather than a simple blowback or a locked-breech gas system, rollers delay the bolt's rearward movement just long enough for pressure to drop to safe levels. That system is a big part of why the MP5/MAC-5 platform has a reputation for a smooth, controllable shooting experience with relatively low felt recoil for a pistol-caliber platform.

What's the barrel and capacity setup?

This configuration ships with a 5.8-inch barrel threaded 1/2x28 and finished with a tri-lug muzzle device, so you can run a suppressor or an original HK-pattern accessory that mounts to the tri-lug adapter. Capacity is 30+1 rounds of 9mm, and it comes with two 30-round magazines. Overall length is about 13.7 inches and weight is roughly 4.6 pounds, sights are a hooded front post with a diopter rear sight, and a two-position thumb safety rounds out the controls.

Is this compatible with existing MP5-pattern accessories?

Yes — Military Armament Corp built the MAC-5/MAC-5K to accept MAC-branded and H&K-pattern parts designed for the MP5K, so stocks, optics mounts, slings, and other accessories built for that ecosystem are generally compatible without modification. That's a meaningful advantage if you already own MP5K accessories or want access to the wide aftermarket built around that platform over the decades.

Who is the MAC-5K built for?

This pistol is aimed at shooters who want the classic roller-delayed shooting experience in pistol form — home defense with a brace or arm stabilizer (subject to your local regulations), suppressor hosts who want a quiet, controllable 9mm platform, and MP5 enthusiasts who want a modern, semi-auto-only version of an iconic design without the cost or paperwork of an original transferable machine gun.

What should California buyers know before ordering?

As a firearm, the MAC-5K ships to a licensed FFL dealer for an in-person transfer and background check, not to a home address. Pistol-caliber, MP5-pattern pistols like this one can be subject to specific configuration rules in California (including restrictions on certain features and accessories), so California buyers should confirm this exact configuration's current legal status with their receiving FFL before ordering. Checkout runs through secure checkout, and no stock-level or shipping-speed claims are made here.

What should you expect for the transfer timeline?

As with any handgun in California, budget for the standard 10-day waiting period between the background check and pickup, a valid Handgun Safety Certificate unless you're exempt, and a DOJ-approved locking device included with the sale. Given how configuration-sensitive MP5-pattern pistols can be under state law, it's worth having your receiving FFL confirm this exact MAC-5K configuration is currently transferable before you place the order rather than after.

Can you add a brace or stabilizer to this pistol?

Arm braces and stabilizing devices for pistols are subject to their own separate federal and state rules, which have shifted more than once in recent years. Don't assume a brace is legal to add just because it physically fits the MAC-5K's receiver — confirm current federal and California-specific rules before purchasing or installing one, since regulations in this area can change with little notice.