From 11 mm to 20 mm – Picatinny Rail Adapter for Air Rifles and Rimfire Systems

Many air rifles, PCP airguns and .22 rimfire rifles come factory-fitted with an 11 mm dovetail rail. This system has proven itself over decades and reliably holds traditional ring mounts – but as soon as you want to switch to a modern Picatinny-compatible scope mount, red dot or thermal clip-on, you hit a wall: the two systems are simply not compatible.

This adapter provides a sound technical solution to exactly that problem. It attaches to the rifle's 11 mm dovetail rail from below, while offering a full-standard 20 mm Picatinny / Weaver (MIL-STD-1913) surface on top.

Construction and Material

The adapter is CNC-machined from aerospace-grade aluminium with a hard-anodised matte black finish. The precision machining ensures parallel surfaces and accurate slot spacing – your optic will sit firm and rattle-free in the mount.

• 9 Picatinny slots — enough range to position a scope or other optic at the correct eye relief
• Two high-strength hex screws — even clamping force secures the adapter firmly to the rifle rail
• Stop pin — prevents the adapter from shifting under recoil or bidirectional load, helping to retain zero
• Low profile (approx. 16 mm height) — keeps the optic close to the bore without unnecessary elevation

Technical Specifications

• Base mounting: — 11 mm dovetail
• Top rail: — 20 mm Picatinny / Weaver (MIL-STD-1913)
• Number of slots: — 9
• Length: — 100 mm
• Mounting length: — 75 mm
• Height: — approx. 16 mm
• Width: — 25 mm (including fixing screws)
• Weight: — approx. 62 g
• Material: — aerospace aluminium
• Finish: — hard anodising, matte black

Package Contents

• 1× — 11 mm to 20 mm Picatinny rail adapter (9 slot)
• 1× — Allen key for the fixing screws

What It Is – and What It Is Not

This adapter is suited for air rifles, PCP systems, .22 LR and similar low-to-medium recoil platforms where only an 11 mm rail is available from the factory, but you wish to use modern Picatinny-compatible accessories.

For high-powered, heavy-recoil centrefire rifles, we recommend a monobloc mount or a scope mount designed directly for a Picatinny rail rather than this adapter.

Who Is It For?

This adapter is aimed at air rifle shooters and rimfire enthusiasts who want to fit modern Picatinny-compatible optics or accessories to a rifle that only has an 11 mm dovetail rail. It is particularly useful when no factory Picatinny rail is available but you prefer to work within the standard mounting system – whether you are fitting a riflescope, a red dot, or a thermal clip-on sight. Installation takes just a few minutes.