Mount

What it means

The mount clamps the scope to the rifle’s rail. Thermal scopes usually take one of two approaches:

• Standard rings. Many have a round tube, often 30 mm, that fits ordinary scope rings. You choose the rings and their height.
• A built-in rail clamp. Others ship with a mount that clamps straight onto a Picatinny or Weaver rail, the slotted rails on most modern rifles. Some are quick-detach (QD), with a lever that lets you take the scope off and put it back without tools.

What it changes in the field

Most “won’t hold zero” stories end at the mount. Common causes: a QD lever that loosens under recoil, a cross-bolt that is narrower than the rail slot so the scope can shift, or a scope put back in a different slot than where it was zeroed.

Height matters too. Thermal scopes with large lenses often sit tall, and on a bolt rifle without an adjustable cheek piece that can leave you without a solid cheek weld. Thermals also often mount farther back than a day scope because of their eye relief.

What to look for

• Fixed or QD. Fixed is simplest and steadiest. A QD mount is worth it only if it is known to return to zero and you will really move the scope.
• Fit. Make sure the cross-bolt fits your rail’s slots snugly.
• Height. Pick the lowest mount that clears the barrel and gives a solid cheek weld.
• Torque. Use a torque driver set to the mount maker’s figures, and mark the rail slot.
• Included or not. Some scopes ship with a mount; others need rings bought separately.

How we use it on this site

We show what the maker says about the mount for riflescopes, including whether it is included. It is not scored.