Buildsheet: Downsizing to a 9mm PCC in a Small Package

We all know how it goes — you find that roll pin on the floor and now you have to build another gun. In this case, it was being gifted a really nice 9mm AR barrel that pushed everything over the edge to put this together. This build is something that had been pondering for considerable time. Now being “forced” to take action, some goals were identified: a compact 9mm, runs on Glock mags, and can be easily suppressed. This build is meant for fun ground squirrel hunting or occasional plinking when/if ammo prices even out.

The Rainier Arms Select Series Barrel was the perfect starting point for this little blaster. At 6 inches, it wasn’t so long that subsonic rounds would go supersonic, since this build is intended to be shot suppressed almost exclusively. The barrel came threaded ½-28mm, making the mating of the SilencerCo Omega 9K easy with a direct thread adapter. The bolt was purchased at a steep discount locally due to the product being discontinued. It’s from Primary Weapon Systems and features a removable carrier weight. The charging handle is the standard Bravo Company USA Gunfighter Medium, giving us increased surface area on the latch mechanism to help clear the sling QD swivel.

The Bootleg Enhanced Upper doesn’t have a forward assist, which would be unnecessary for a pistol-caliber build, and it saves us a little bit of weight (1.7 ounces) over a standard Mil-spec upper receiver. The handguard is extremely easy to install, given the camming mechanism, and at 4 inches is a great length for the barrel. And, of course, M-LOK lets us mount stuff like the SureFire Scout light with Magpul mount to position the light higher at the 1 o’clock position for thumb activation. One gripe is the lack of M-LOK on the bottom, but we can get past this.

The lower receiver was purchased locally and is a Spikes Tactical “Spider” stripped lower. The lower included takedown pins and has a last round bolt hold-open device installed. A standard CMMG lower parts kit fills in the rest of the guts; they may not be flashy, but the CMMG kit fit and didn’t break the bank for quality parts. We’d like to upgrade the trigger to the CMC Single Stage 3.5lb 9mm PCC Flat trigger in the future. The Magpul MOE-K is an incredibly compact and thin grip that adds little in the way of weight and sits flush when a Magpul 21-round magazine or Elite Tactical Systems 22-round magazine is installed. An important consideration for storage of the gun.

To keep the overall length of the build small and functional, a Maxim Defense CQB PDW brace was selected. These can come with a PCC weight buffer for use in blowback systems where more weight is necessary for reliable function. Once fully extended, the Maxim brace goes from 5.3 to 9.2 inches, providing sufficient length of pull for us for control.

The PDW brace also has quick detach mounts machined into the extension for attaching a sling. Since this package is small enough that a single-point sling would work, we selected the Edgar Sherman Design M81 sling with the use of an Impact Weapon Components 2-to-1 Point TriGlide. This little piece takes a two-point sling with quick detach mounts and allows you to make it into a single-point sling quickly. The sling also has the added benefit of an elastic band sewn in for storing the sling on top of itself for when the firearm is in a case or a bag. Topping off the build is the bombproof Aimpoint H-1 red dot riding in a LaRue Tactical quick detach, lower 1/3 cowitness mount.

The culmination of parts is a handy and capable package that fills the given parameters of being small and using Glock magazines. The benefit of Glock magazines is the ability to tailor the size to your needs, ranging from 10 and up to 50 rounds. This little guy tips the scales at 6.76 pounds, unloaded — not the lightest weight of builds, but this is acceptable given the heavy blowback components. Weight could be shaved replacing the PDW brace (but we’d sacrifice overall length) or using a lighter optic/mount combo. It’s all give and take, and the important thing is that we have a fun package that can be upgraded as needed or wanted. 

Components

• Bootleg Inc Enhanced AR-15 Upper Receiver: $180
• Spikes Tactical 9mm Spider Stripped Lower: $180
• Bootleg Inc M-LOK 4-inch Handguard: $136
• Primary Weapons Systems 9mm Bolt: Discontinued
• Rainier Arms Select 6-inch 9mm Barrel: $150
• Maxim Defense CQB Brace: $190
• CMMG Lower Parks Kit: $69
• Magpul MOE-K Grip: $19
• Bravo Company USA Charging Handle: $40

Extras

• SilencerCo Omega 9K: $865
• Aimpoint H-1: Discontinued
• LaRue Tactical LT660: $107
• SureFire M600 Scout Light: $297 (Brownell's Affiliate Price: $296)
• Magpul M-LOK Offset Light/Optic Mount: $35
• KRISS MagEx2 Extension: $30
• Glock 17 Magazine: $38
• Edgar Sherman M81 Sling: $50
• X2 Magpul Quick Detach Swivels: $30
• Impact Weapon Components 2-to-1 TriGlide: $20

Total: $2,626

BUILDSHEETS: PAST AND PRESENT

• Going OFFGRID
• A Different Kind of Thin Blue Line
• This folder is Mk18-ish
• Light and Bright
• The Coyote Crusher
• The Contractor Service Rifle
• The SnipAR Rifle
• Building out the .224 Valkyrie
• M16A4 OIF Edition
• Not Just AR's: SBR AK
• 5.45 AK: Starting with the Arsenal 104
• The Real Call of Duty Soulful Wanderer
• Hacksaw Special: Making short rifles even shorter.
• Softening the AR-10
• Sleeper Retro AR Clone
• Government Surplus

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