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Scope dovetail rails: 11 mm (European) and 3/8 in (US), and Weaver

What are 11 mm and 3/8 in dovetail and Weaver rail dimensions? · Standard part · basis: Published dimensions only (Optics Trade technical article; Brownells GunTech via AccurateShooter); groove depth and height are not standardized, so no file

Also called: 11mm dovetail rail dimensions, 3/8 dovetail rail, airgun scope rail, weaver rail dimensions, rimfire dovetail, 11mm vs 3/8 dovetail

Exact dimensions. True size, with no printing tolerance added.

sizes
3 in table

Notes

  • Airguns, rimfire rifles and many airsoft and crossbow scopes use a plain dovetail instead of Picatinny.
  • 11 mm dovetail: 11 mm across the top with 60° sides (the European standard). 3/8 in dovetail: 12.7 mm across the top with 45° sides (the US standard); the 3/8 in is measured across the bottom. Their depths and heights vary by maker, so Xem publishes no file: measure your rail's height before designing a clamp.
  • Weaver: grooves .180 in wide, with no standard centre-to-centre spacing.
  • Picatinny (MIL-STD-1913) is fully specified: see its page for the complete profile and files.

Scope dovetail rails: 11 mm (European) and 3/8 in (US), and Weaver size chart

railtop widthside anglegroove
11 mm dovetail11 mm60°none
3/8 in dovetail12.7 mm (3/8 in across the bottom)45°none
Weavernot standardized—.180 in wide, spacing not standardized

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

Optics Trade11 mm and 3/8" dovetailswebPublisher's page; dimensions are facts
AccurateShooter (Brownells GunTech)Picatinny vs. Weaver rail specificationswebPublisher's page; dimensions are facts

Xem scan

File coming

No downloadable true-size file yet: the published figures do not fix the whole shape, and Xem never guesses a number. A measured scan is planned; request it and it moves up.

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Plain text: sheet.txt · JSON: /api/geometry?object=scope-dovetail-rails

length
Schematic, not to scale.

Fits with

Picatinny rail (MIL-STD-1913): profile, grooves and mount jaw, isometric render of a generated part
Picatinny rail (MIL-STD-1913): profile, grooves and mount jaw21.209×9.322 mm★ 6 files
Dovetail rail and slide mount (60°), isometric render of a generated part
Dovetail rail and slide mount (60°)32.0×80.0×16.0 mm★ 3 files

Questions

Are 11 mm and 3/8 in dovetails interchangeable?

Not with ordinary mounts: 11 mm is 11 mm wide at 60°, 3/8 in is 12.7 mm at 45°; some mounts with reversible clamps fit both.