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 ?
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.
The supplied 20 MOA Picatinny sight rail is a nice touch, as is the rail to attach a bipod, where it suits you best.
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.
ACTION TYPE: Pump, GAUGE: 12, BARREL: 1-1/2", chrome lined, 3" chamber, CHOKE: Ported cylinder tube, CAPACITY: 5+1 [2-3/4"'' shells], 4+1 [3"], WEIGHT: 7 pounds, OVERALL LENGTH: 39", STOCK: Synthetic, FOREARM: Synthetic, with rail, SIGHT BASE: Picatinny sight rail, SIGHTS: LPA adjustable ghost ring rear, fiber-optic front, RETAIL: $417
The sight rail attaches to the gas block using 8-32x1/2" stainless steel socket head cap screws.
The PAS-12 can be had with an adjustable rear sight, but the RG-RIC model comes with an installed sight rail.