These spotting rifles were mounted co-axially to the main gun, and fired tracer ammunition ballistically matched to the gun itself.
12.
The weapon was aimed via a spotting rifle, which fired . 50 BMG rounds whose trajectory matched that of the main weapon.
13.
Although the spotting rifle could conceivably be used in an antipersonnel role, historical U . S . military doctrine strongly discouraged this use.
14.
Direct fire is limited to 1, 800 meters using the optical sight with stadiametric rangefinder or 1, 200 meters using the spotting rifle.
15.
The 106 mm M40 recoilless rifle is aimed using a 12.7 mm barrel-mounted spotting rifle for which 100 rounds of ammunition are carried.
16.
The M27 was also considered too heavy by the U . S . Army and had a disappointing effective range due to the lack of a spotting rifle.
17.
Where a vehicle, such as the M50 Ontos, used multiple barrels, spotting rifles were usually provided for each barrel so that each could be accurately boresighted to its own barrel.
18.
It is a man-portable weapon system consisting of the MK153 launcher, the MK 3 encased HEDP rocket, the MK 6 encased HEAA rocket, and the MK217 spotting rifle cartridge.
19.
Four of the rifles also had . 50-caliber coaxial spotting rifles attached, each of which fired a round with the same trajectory as the 106 mm round, and that gave off a puff of smoke on impact.
20.
The launcher consists of a fiberglass launch tube, a 9 mm spotting rifle, an electro-mechanical firing mechanism, open battle sights and a mount for the MK42 Day Sight and AN / PVS-17B night sights.
