sight rail

sight rail

One of a series of horizontal rails, usually boards supported at both ends, which are used to check the gradient of a pipe in a trench; the rails are adjusted by sighting a line having the desired gradient; the rails then establish a line from which the bottom of the trench can be measured.
References in periodicals archive ?
The 9CT combines the aesthetics of an iconic SMG with features such as a sight rail and M-Lok forend.
The body, which the FCU calls the grip module, provides the integral pistol grip, sight rail and just about everything else one could put into such a small package.
Trench-style sight rail accommodates suppressor sights, and beveled sight rail design eases holstering.
The Blakguard is a neutral draw with "trench" style sight rail accommodating most sights.
You likely have customers who don't think they need a light or light/laser unit to go on the integral sight rail of their pistols.
A 6-inch scope sight rail is affixed to the receiver with four slotted 6-48 screws.
It is the first sight rail passengers from the south see when they come into Newcastle Gateshead.
The mention of the "7/32 hex screw" for the sight rail is a distortion of an error in the manual; it calls for a 7/32 wrench.
Here, it's attached to the sight rail of my Volquartsen/Ruger.
No excessive force is required, but you do have to pay attention that the pistol enters the sleeve low enough for the keyway on the sleeve to align with the sight rail on the bottom of the pistol frame.