F5-ACR Gen 3 Stock — G3 / HK91 / HK51 (Turn-Key, Includes Recoil Rod & Spring)
PRESALE — Limited Production Run — Order now and save! Fulfilment expected mid-late August
The F5-ACR Gen 3 Stock for G3/HK91/HK51 is the most ergonomic, feature-rich, and rugged side-folding stock available for the G3/HK91/HK51 platform. The F5-ACR Gen 3 brings the same CNC-machined, fully adjustable folding stock trusted across the F5-ACR lineup to G3-pattern rifles — now built as a complete, turn-key kit. Unlike other G3 stock adapters that leave you sourcing a separate recoil rod and spring, this kit includes the recoil rod and spring assembly, so it drops onto your rifle and is ready to run — no gunsmith, no scavenging surplus parts, no compatibility guesswork.
Why This Kit Is Different
Most G3/HK91 folding stock adapters on the market require you to source your own recoil rod and spring separately, or reuse a worn factory assembly — and few match the F5-ACR’s ergonomics or adjustability. The F5-ACR Gen 3 for G3/HK91/HK51 sets a new bar on both fronts:
- Most ergonomic and feature-rich side-folder for this platform — fully adjustable cheek riser, not just a fixed folding hinge
- True turn-key installation — recoil rod and spring included, not sold separately
- Rugged, duty-grade construction — CNC-machined 6061 billet aluminum built to outlast fixed and folding OEM stocks alike
- Drop-in fit — no gunsmithing or fitting required
- One box, one install — stock, chassis, and recoil assembly ship together
Features
- Fully adjustable cheek riser — dial in cheek weld for optics, red dots, LPVOs, or night vision
- Folds without interfering with function — fire while folded on supported configurations
- CNC-machined 6061 billet aluminum chassis for a rock-solid, repeatable lockup
- Reinforced polymer stock body engineered for weight savings without sacrificing durability
- Slip-fit tolerances for minimal play under recoil
- Compact, side-folding design built for transport, vehicle carry, and storage
- Compatible with G3, HK91, HK51, and PTR91-pattern rifles and clones
What’s in the Box
- F5-ACR Gen 3 folding stock chassis with adjustable cheek riser
- G3/HK91/HK51-pattern recoil rod
- Recoil spring
- All hardware needed for a complete, turn-key install
Specs Snapshot
| Spec | Detail |
|---|---|
| Material | CNC-machined 6061 aluminum + reinforced polymer |
| Finish/Colors | Cerakote Black, OD Green, FDE |
| Fold Direction | Side-folding |
| Cheek Piece | Fully adjustable (Gen 3 exclusive) |
| Recoil Assembly | Recoil rod + spring included |
| Platform Fit | HK G3, HK91, HK51, PTR91 and G3-pattern clones |
| Installation | Turn-key / drop-in — no gunsmith required |
| Origin | Made in USA |
Presale Terms
This is a limited-production presale item. Order now to reserve your place in the production run — Order now and save! Fulfilment expected mid-late August.
Built for G3 Owners Who Want More Than an Adapter
Other options on the market give you a folding hinge and call it done. The F5-ACR Gen 3 gives G3 and HK91/51 owners genuine ergonomic adjustability, rugged CNC construction, and a true turn-key install — without hunting down a compatible recoil rod and spring separately.
Reserve your F5-ACR Gen 3 Stock for G3/HK91/HK51 today — the most ergonomic, feature-rich, rugged side-folder for this platform. Presale, limited run.
