Arca-Swiss
A dovetail rail and clamp standard for tripod heads. A rail or plate on the rifle slides into an Arca clamp on the head and locks with a knob or lever, so the rifle goes on and off the tripod in seconds.
What it means
Arca-Swiss is a dovetail: a rail with angled edges, about 38 mm (1.5 inches) wide, that slides into a matching clamp. The name comes from the Swiss camera maker whose quick-release plate became the common standard. Today almost every shooting head, from ball heads to leveling heads, has an Arca clamp on top.
On a rifle the rail usually fastens to the M-LOK slots on the handguard or under the stock, or comes built into a chassis. Some clamps also take a Picatinny rail; a dual clamp does both.
What it changes in the field
- Speed. Rail into clamp, flip the lever, and the rifle is locked to the tripod. Off again for a walk to the next stand.
- Rigidity. A long rail clamped along its length holds tighter than a yoke or saddle, which matters when you are watching through a thermal at night and do not want the reticle drifting.
- Balance. A long rail lets you slide the rifle fore and aft to balance a heavy scope or light.
What to look for
- Rail length that fits your handguard and leaves room to slide for balance.
- Clamp type: a lever clamp is faster; a screw-knob clamp fits slightly out-of-spec rails.
- Safety stops on the rail ends so a loose clamp cannot let the rifle slide off.
How we use it on this site
Tripod pages say whether the top as sold takes an Arca rail. Most bare tripods do not: they have a 3/8-16 stud for a head, and the head brings the clamp.