Almost everything written about mounting optics assumes a Picatinny rail, because almost everything written about mounting optics is written in America. Britain is different. The single most common receiver interface in this country is not Picatinny and not M-LOK — it is the 11 mm dovetail, a plain machined groove that appears on the overwhelming majority of air rifles sold here and on a great many rimfires. If you have just bought a set of rings and discovered they will not go anywhere near your rifle, this is almost certainly why.
This guide explains what the dovetail is, how to measure yours, what you need to buy to get a modern optic onto it — and, straightforwardly, the fact that we do not currently stock the part that does the converting.
What an 11 mm dovetail actually is
A dovetail is a groove machined directly into the top of the receiver, with two angled flanks that a ring clamps against. There are no transverse slots. That is the whole difference: a Picatinny or Weaver rail resists recoil by dropping a crossbolt or recoil key into a slot cut across the rail, while a dovetail resists it purely by clamping friction against the angled flanks.
The name is loose, and that looseness is the source of most fitment mistakes. "11 mm" describes the nominal width across the widest part of the groove, but the family in circulation includes:
- 9.5 mm, often sold as 3/8 inch. Common on older and imported rimfires. Many rings marketed as 11 mm will also close down onto this, but not all.
- 11 mm. The de facto standard on European air rifles, and the size most dovetail rings are cut for.
- 13 mm and 13.5 mm. Found on some heavier receivers. An 11 mm ring will not open far enough for these.
- Dovetails with arrestor holes. Some receivers add one or more small holes or a machined recess in the groove floor, intended to take a recoil arrestor pin on the ring or the adapter.
Measure before you order. Put a vernier calliper across the widest point of the groove and write the number down. This takes ten seconds and prevents the single most common returned order in this category.
Why spring-piston air rifles eat scope mounts
This is the part that catches people who have only mounted optics on centrefires. A recoiling spring-piston air rifle produces a bidirectional impulse: the piston slams forward, the rifle lurches back, and then the whole thing reverses. A conventional centrefire rifle only ever pushes the scope rearwards relative to the rifle. An air rifle pushes it both ways, hard, several times a second of trigger time.
The practical consequences are worth stating clearly, because they explain why the arrestor pin is not optional:
- Friction alone will not hold. Rings clamped to a smooth dovetail will creep forwards over a few hundred shots. You will read this as the scope losing zero.
- Use the arrestor. If your receiver has an arrestor hole, use rings or an adapter with a pin that engages it. If it does not, a firm clamp plus a scope stop is the fallback.
- Check the scope is rated for it. Not every rifle scope is built to survive bidirectional recoil, and a scope that is perfectly happy on a .308 can fail on a magnum springer. Check the manufacturer's own statement before mounting.
- Pre-charged pneumatics are gentler. A PCP has almost no recoil, so the mounting problem is one of geometry rather than survival — but the dovetail measurement question is exactly the same.
Your two routes onto a dovetail
| Route | What it is | Suits | Trade-off |
|---|---|---|---|
| Dovetail rings | Rings whose bases clamp the dovetail flanks directly | Traditional scopes with a 1-inch or 30 mm tube | Lowest sight line; ties you to that one rifle |
| Dovetail-to-Picatinny adapter | A short rail that clamps the dovetail and presents a Picatinny top | Any modern optic, including red dots and one-piece mounts | Raises the sight line; adds a second clamped joint |
The adapter is by far the more flexible answer, and it is the one most people end up wanting, because it converts the rifle to the interface that the rest of the optics world is built around. Once a Picatinny top is in place, everything in our rifle scope rings and red dot sight mounts ranges becomes available to you.
Be aware of what it costs you in geometry. Stacking an adapter under the rings raises the optical centreline, and a higher sight line means a larger offset between the bore and your line of sight at close range — which matters a great deal on an air rifle used at 20 to 30 m. Our mount height chart and zero distance chart both cover the arithmetic.
The honest bit: we do not stock a dovetail adapter
We would rather tell you this on a guide page than have you discover it after the parcel arrives.
Every ring and mount we currently stock clamps to a Picatinny or Weaver rail. None of them will fit an 11 mm dovetail, and we do not at present sell a dovetail-to-Picatinny adapter. That applies to the whole Warne scope mount range — both the Maxima quick-detach rings and the lighter HyperLite rings are described by Warne as clamping to a standard Picatinny or Weaver rail, and they are not dovetail rings — and equally to the Burris XTR Signature rings, whose specification lists rail fit as Picatinny / Weaver.
So if your rifle has a dovetail, the order is: source the dovetail-to-Picatinny adapter elsewhere first, fit it, then buy rings from us to sit on top of it. Any UK airgun dealer will have adapters in stock, and once you know your groove measurement you can buy with confidence. It is a genuine gap in our range and we are not going to dress it up as anything else.
Choosing the optic itself
Two things matter more on an air rifle than on anything else.
- Close parallax. Much air rifle shooting happens between 10 and 35 m. A scope whose parallax is fixed at 100 m will not give you a crisp picture there. Look for adjustable parallax or an air-rifle-specific fixed setting.
- Ring height against objective diameter. A big objective bell forces high rings, which worsens the close-range offset just described. On an air rifle, a modest objective is usually the better answer.
If you are putting a red dot on instead, our best red dot sights under £300 guide covers the sensible end of that market, and the rimfire and .22LR optics collection is the closest thing we have to a dovetail-adjacent shortlist — with the same caveat that the mounting still has to be solved separately.
Where the law sits
Optics themselves are not licensed anywhere in the United Kingdom. Air weapons are treated differently across the four nations, though, and Scotland in particular has its own certificate scheme. We have written that up properly in what optics can you use on an air rifle in the UK, with the wider framework in do you need a licence for a rifle scope, red dot or torch. Neither piece is legal advice — check your own position with your force.
Frequently asked questions
Will Picatinny rings fit an 11 mm dovetail?
No. A Picatinny ring clamps a raised rail with transverse slots; a dovetail is a recessed groove with angled flanks and no slots. The two interfaces have nothing in common, and no amount of tightening will make one work on the other.
Do you sell an 11 mm dovetail adapter?
Not at present. Every ring and mount we stock is for a Picatinny or Weaver rail, so a dovetail adapter has to be sourced separately before our rings will fit your rifle.
Is my rifle 9.5 mm, 11 mm or 13 mm?
Measure it. A vernier calliper across the widest part of the groove gives you the answer in seconds, and manufacturers' catalogue descriptions are not always reliable on this point.
Why does my air rifle keep shifting its zero?
On a spring-piston rifle, almost always because the mount is creeping along the dovetail under bidirectional recoil. Fit an arrestor pin into the receiver's arrestor hole, or add a scope stop, and re-zero.
Can I put a red dot sight on an air rifle?
Mechanically yes, once the dovetail is converted to Picatinny or you have a dovetail-footed sight. Whether it suits your shooting is a separate question — a red dot has no magnification, which matters at air rifle ranges on small quarry.
When your mounting is sorted, browse rifle scopes, red dot sights and rimfire and .22LR optics, or read our guides to scopes for a .22LR rimfire and Tikka, Sako, CZ, Blaser and Weaver mounting. The mounts and rings buyer's guide covers the Picatinny side in full. Everything we sell is held in our UK warehouse and dispatched tracked, with no import charges to follow — the detail is in buying optics in the UK.