“Backseat” CQB .300 Blackout 7.5″ AR-15 Pistol Kit – Team Dream Build
Features
- Compact .300 Blackout AR-15 pistol kit built around close-quarters handling and easy transport
- 7.5″ AT3 .300 Blackout barrel keeps the build short, handy, and well-suited for tight spaces
- AT3 Pro Quad Rail gives the pistol a sturdy front end with plenty of accessory mounting space
- KAK extended slimline flash can helps direct blast forward on a short-barrel .300 Blackout setup
- Sylvan Arms folding adapter and SB Tactical brace help reduce overall storage and transport length
- AT3 ALPHA green dot and AT3 DELTA 3x magnifier provide a fast close-range optic setup with added flexibility
- Streamlight ProTac Rail Mount 1L adds a compact weapon light for low-light use
- Wojtek adjustable gas block allows tuning for different .300 Blackout loads and suppressor setups
- Magpul .300 Blackout PMAG helps keep .300 Blackout ammunition separated from standard 5.56 magazines
The “Backseat” CQB .300 Blackout AR-15 Pistol Kit is built around a practical compact setup for close-range use, tight spaces, and transport in a smaller everyday-style bag instead of a full-size rifle case. The 7.5″ .300 Blackout barrel, folding adapter, pistol brace, quad rail, weapon light, red dot, and magnifier give this build a serious close-range layout without trying to be a long-range rifle. It is heavier than a minimalist pistol, but that weight comes from purpose-built parts selected for secure mounting, folding storage, and a robust feel behind the gun.
Note: This build includes a pistol brace and folding adapter. Firearm configuration rules, brace treatment, transport rules, and NFA requirements can vary and may change over time. It is the purchaser’s responsibility to ensure the final configuration complies with all applicable federal, state, and local laws before assembly or use. Do not configure this build with a stock unless all applicable NFA requirements have been met.
Kit Note: This product is sold as a parts kit, and final assembly is up to the purchaser. Parts and accessories are subject to change due to unforeseen shortages, compatibility updates, or compliance changes. Any substitutions will be of equal or greater value and will be noted in this product listing.
Specifications
- Build: Backseat CQB .300 Blackout 7.5″ AR-15 Pistol Kit
- Platform: AR-15
- Caliber: .300 Blackout
- Barrel Length: 7.5″
- Barrel Profile: Medium Profile
- Gas System: Pistol-Length
- Gas Block: Adjustable, .750″
- Handguard Length: 7″
- Handguard Type: Free Float Quad Rail
- Upper Receiver: Slick Side Billet AR-15 Upper Receiver
- Lower Receiver: To Be Confirmed
- Bolt Carrier Group: Black Nitride AR-15 BCG
- Charging Handle: Breek Arms WARHAMMER Mod 2 Ambidextrous AR-15 Charging Handle
- Muzzle Device: KAK Extended Slimline Flash Can
- Muzzle Device Thread Pitch: 5/8×24
- Trigger: AT3 GI Mil-Spec 6 lb Single-Stage Flat Trigger
- Brace: SB Tactical SBA3X AR-15 Pistol Brace
- Folding Adapter: Sylvan Arms Gen 5 AR-15 Folding Adapter
- Grip: Ergo 2 Flat Top AR-15/AR-10 Grip
- Buffer System: Mil-Spec Buffer Tube, Carbine Buffer, Carbine Buffer Spring
- Primary Optic: AT3 ALPHA Micro 2 MOA Green Dot Sight
- Magnifier: AT3 DELTA 3x Red Dot Magnifier with QD Flip-to-Side Mount
- Weapon Light: Streamlight ProTac Rail Mount 1L Dual Fuel Weapon Light
- Magazine: Magpul PMAG M3 .300 Blackout 20-Round Magazine
What’s Included
Upper Assembly Components:
- AT3 Tactical AR-15 Barrel – 7.5″ – .300 Blackout – Medium Profile – Pistol-Length
- AT3 Slick Side Billet Upper Receiver for AR-15
- AT3 Pro Quad Rail Free Float AR-15 Handguard – 7″
- KAK Industry 5″ Extended Slimline Flash Can – 5/8×24 – .458 Caliber & Smaller
- Breek Arms WARHAMMER Mod 2 Ambidextrous AR-15 Charging Handle
- AT3 AR-15 Bolt Carrier Group – Black Nitride – .223/5.56 NATO, .300 Blackout, .350 Legend
- Wojtek Adjustable Gas Block – .750″ w/ Wrench Kit
- AR-15 Pistol-Length Gas Tube
- AR-15 Gas Tube Roll Pin
Lower Assembly Components:
- AT3™ AT-15 Stripped Lower Receiver
- Sylvan Arms AR-15 Flared Magwell with Integral Trigger Guard
- AT3 GI Mil-Spec 6 lb Single-Stage AR-15 Trigger – Flat
- Armaspec Anti-Walk Trigger and Hammer Pins
- AT3 Ambidextrous AR-15 Safety Selector
- Magpul Enhanced AR-15 Magazine Release
- AT3 AR-15 Mil-Spec Bolt Catch
- AT3 Bolt Catch Plunger
- AT3 Bolt Catch Spring
- AT3 Bolt Catch Roll Pin
- AT3 Mil-Spec AR-15 Magazine Catch
- AT3 Mil-Spec AR-15 Magazine Catch Button
- AT3 Mil-Spec AR-15 Magazine Catch Spring
- AT3 Takedown Pin
- AT3 Pivot Pin
- AT3 Takedown/Pivot Pin Detent Spring
- AT3 Takedown/Pivot Pin Detent
- AT3 FU-BAG AR-15 Lost Parts Kit – Springs, Detents, Replacement Components
Buffer System & Furniture:
- SB Tactical SBA3X AR-15 Pistol Brace – No Buffer Tube
- Sylvan Arms Gen 5 AR-15 Folding Stock Adapter
- AT3 Mil-Spec AR-15 Buffer Tube
- AT3 Carbine Buffer – 3.0 oz
- AT3 Carbine Buffer Spring for AR-15
- AT3 Mil-Spec End Plate for AR-15
- AT3 Castle Nut for AR-15 Buffer Tubes
- Ergo 2 Flat Top AR-15/AR-10 Grip – SureGrip
Optics, Sights & Light:
- AT3 ALPHA Micro 2 MOA Green Dot Sight – Shake Awake – Cantilever Riser Mount
- AT3 DELTA 3x Red Dot Magnifier with QD Flip-to-Side Mount
- Streamlight ProTac Rail Mount 1L Dual Fuel Weapon Light – Picatinny Rail Mount – 350 Lumens
- Magpul MBUS 3 Front Sight
- Magpul MBUS 3 Rear Sight
Magazine & Tools:
