JMac Customs 8" Skeleton Folding Stock KUSA KP9, Tan Finish , SS-8RP-T+FM-SM-1913
Product Description
The JMac Customs® SS-8RP 8" Skeleton Folding Stock Kit in Tan Finish with 1913 Folding Mechanism (SKU: SS-8RP-T+FM-SM-1913) is a complete, duty-grade modular stock system purpose-built for the Kalashnikov USA KP-9, KR-9 SBR, and any platform equipped with a rear MIL-STD-1913 Picatinny rail interface. Precision-machined in the USA, this package pairs JMac’s 8-inch skeletonized aluminum stock bar with a pre-installed slip-resistant rubber recoil pad and their ultra-rugged steel 1913 folding hinge mechanism.
Engineered from lightweight, high-tensile 7075-T6 aircraft-grade billet aluminum and finished in a durable Tan anodized coating, the SS-8RP stock bar provides unmatched structural rigidity without unnecessary weight. The rear features a grooved rubber buttpad that anchors securely into the shoulder pocket under rapid-fire strings, along with an integrated anti-rotation QD sling socket for single-point or two-point sling mounting. The top strut includes pre-drilled riser holes, making it directly compatible with JMac Customs polymer cheek risers for dialing in perfect optic sightlines.
The included FM-SM-1913 folding mechanism is CNC-machined from heat-treated ordnance-grade steel with a black nitride finish. Featuring a positive-locking detent, it allows the stock to lock rigidly into battery when deployed and snap securely into the folded position for vehicle stowage or concealed carry. The hinge is fully reversible, giving the shooter the flexibility to fold to the left or right to avoid interference with optics, charging handles, or side selector levers.
*Armorer Bench Notes & Real-World Staging Guidance:*
Fitment Matrix: Direct mounting to any standard rear MIL-STD-1913 Picatinny rail interface. Optimized for the Kalashnikov USA KP-9 / KR-9 (when fitted with a rear 1913 trunnion adapter or factory rear 1913 rail), SIG MCX / MPX, Ruger LC Carbine, AK-V, and stamped/milled AK receivers with rear 1913 adapters. Ensure all NFA rules apply if installing on a pistol platform (creates a Short Barreled Rifle). When securing the stock strut to the folding mech with the included countersunk screws, apply medium-strength blue threadlocker and torque to 25–30 in-lbs. Torque the 1913 rail cross-bolt to 35–40 in-lbs.
- Ensure the host firearm is completely clear, magazine removed, and chamber visually and physically verified empty.
- Determine preferred folding orientation (left-folding or right-folding) and assemble the SS-8RP stock bar to the FM-SM-1913 folding hinge using the provided hardware and blue threadlocker.
- Loosen the 1913 clamp cross-bolt and position the folding mechanism onto the rear Picatinny rail slots of the firearm.
- Tighten the clamp bolt evenly with an inch-pound torque wrench to 35–40 in-lbs, verifying solid lockup with zero lateral play in both deployed and stowed positions.
Key Features
- Complete Folding Stock System: Includes the 8" skeletonized stock bar with rubber buttpad (SS-8RP-T) and the 1913 steel folding mechanism (FM-SM-1913).
- KP-9 & 1913 Universal Fitment: Clamps directly to any standard rear Picatinny rail trunnion or adapter plate.
- Rugged 7075-T6 Aluminum Construction: Delivers extreme strength-to-weight ratio and rigidity under harsh field abuse.
- Pre-Installed Rubber Buttpad: Textured rubber pad cushions recoil impulses and eliminates slippage against plate carriers or clothing.
- Reversible Side-Folding Steel Hinge: Heavy-duty steel mechanism can be configured to fold left or right to clear accessories or controls.
- Integrated QD Sling Swivel Cup: Features a built-in quick-detach sling mounting point at the heel of the stock.
- Modular Cheek Riser Ready: Pre-drilled mounting provisions along the top spine accept JMac cheek risers for tall optic mounts.
- Durable Tan Finish: Corrosion- and wear-resistant Tan anodized treatment engineered to withstand hard operational environments.
- Made in the USA: Proudly designed, CNC-machined, and assembled in the United States by JMac Customs.
Product Specifications
- Brand: JMac Customs®
- Model/Series: 8" Skeleton Folding Stock w/ Rubber Pad & 1913 Mech
- MPN / SKU: SS-8RP-T+FM-SM-1913 (SS-8RP-T / FM-SM-1913)
- Stock Length: 8.00 Inches (Approx. 8.75" Overall Length with Hinge and Pad)
- Interface: MIL-STD-1913 Picatinny Rail Clamp
- Folding Direction: Reversible (Left or Right Side-Folding)
- Compatibility: Kalashnikov USA KP-9, KR-9, AK Platforms w/ 1913 Adapter, SIG MCX/MPX
- Stock Material: 7075-T6 Billet Aluminum (Tan Anodized)
- Hinge Material: Heat-Treated 4140 Steel (Black Nitride)
- Buttpad: High-Density Textured Rubber
- Sling Attachment: Integrated Rear Steel QD Socket
- Country of Origin: United States
