Scoping A Rimfire Or Air Rifle? Start Here.
You picked up a .22 LR or a pellet gun and you're ready to mount a scope — but instead of the Picatinny or Weaver rail you're used to, there's a slim trapezoidal groove running along the top of the receiver. That's a dovetail rail, and it's the standard mounting system for rimfires and airguns worldwide. Here's everything you need to know to get set up right.
What Is A Dovetail Rail?
A dovetail rail is simply a narrow, trapezoid-shaped groove machined into the top of a receiver. Instead of the cross-slotted Picatinny system used on most centerfire rifles, dovetail rings clamp directly into this groove from above. They're sometimes called "tip-off" mounts — because rings can literally tip on or off the rail quickly, like taking a picture off a hook.
They're lighter duty than a Picatinny setup, but perfectly matched to the lower recoil of rimfire and airgun platforms. If your rifle has one, you just need the right rings — and a little know-how.
3/8" vs. 11mm: Which Size Do You Have?
Dovetail rails come in two common sizes. The names sound more different than they actually are — in practice, they overlap significantly, and many modern rings are built to cover both.
American Rimfire Standard
3/8"
≈ 9.5mm Wide
The traditional American rimfire standard. Found on most U.S.-made .22 rifles — Ruger, Marlin, Savage rimfires typically run this groove width.
To confirm: measure flat-bottom to flat-bottom (skip the angled sides). Around 0.38" (~9.7mm) means you're on a 3/8" rail.
Airgun & European Size
11mm
9.5mm – 14mm Actual Range
Common on European airguns and PCP platforms. "11mm" is a nominal label — actual widths vary from 9.5mm all the way to 14mm depending on the manufacturer.
To confirm: measure flat-bottom to flat-bottom. Around 0.50" (~12.7mm) puts you in 11mm territory.
Four Things To Know Before You Buy
Tip-Off (Quick-Detach) Rings
If you swap optics often or store your rifle without the scope, tip-off rings are worth considering. Instead of permanent bolts, they use thumbscrews — unscrew a knob on each ring and the scope tips off the rail without disturbing the clamped base. Weaver's Quad-Lock Tip-Off rings are a classic example: two straps per ring, four screws total, lightweight aluminum construction that still holds tight. They sit slightly taller than fixed rings, so make sure you have adequate rail height — but for a .22 truck gun or range gun you regularly store or swap, they're a genuine convenience upgrade.
Already Own Weaver or Picatinny Rings? Use An Adapter.
If you have a quality Weaver or Picatinny ring set and want to use it on a dovetail rifle, dovetail-to-Weaver adapters let you do exactly that. These are two-piece inserts that fit inside your existing ring's base clamps and convert them to grip a dovetail rail instead. It adds minimal height and one extra piece to install — but it's a smart way to move a scope from a centerfire to a rimfire without buying an entirely new ring set.
Spring-Piston Airguns Need A Scope Stop Pin
Spring-piston airguns (springers) are unique — they recoil both forward and backward. This double-recoil can jar a scope loose even on a mild .177, and it's notoriously hard on optics. The solution is a scope stop pin: a small vertical peg on the ring or base that seats into a crosswise notch on the rifle's rail. If the scope tries to shift, the pin catches it. If your airgun has a notch (common on Weihrauch and Air Arms), use rings with a stop pin. If it has a flat plate or groove (Gamo or some Chinese guns), clamp down extra tight — a pin-style ring may not fit.
Go As Low As You Can On Ring Height
Dovetail rings come in low, medium, and high heights — just like Picatinny rings. Choose the lowest height that still clears your objective bell and barrel. Lower rings improve cheek weld, reduce weight, and keep the setup compact. On a lightweight rimfire or airgun, that extra inch of ring height adds up more than you'd think.
Quick Reference: What To Use For Your Platform
| Platform | Rail Size | Best Option |
|---|---|---|
| American .22 LR Rifle | 3/8" (≈9.5mm) | Tip-off or fixed rimfire rings |
| European Airgun / PCP | 11mm (9.5–14mm) | 11mm rings or adjustable-fit rings |
| Spring-Piston (Springer) | 11mm typically | Rings with a scope stop pin |
| Already Own Weaver Rings | Either size | Dovetail-to-Weaver adapter insert |
| Swapping Scopes Frequently | Either size | Tip-off quick-detach rings |
"Small-Bore Rifles Deserve A Rock-Solid Scope Setup Too."
Measure your rail. Match your rings. Add a stop pin if you're running a springer.
Weaver carries dedicated dovetail rings, Tip-Off quick-detach rings, and adapters for both 3/8" and 11mm rails. Follow the advice above and your rimfire or airgun setup will hold zero and hold up — no matter what.