The Marksman carbine is a semi-automatic, medium-power rifle with a 20-round magazine. Mounted with an enhanced-zoom scope that shares the same reticle as the anti-materiel rifle and sniper rifle, it is highly accurate and deadly at long range with a Gunsskill of 100. With its good damage, an extremely high rate of fire and a good-sized magazine, it can deal a large amount of damage per second, making it versatile and useful against most enemies.
Durability
The marksman carbine can fire a total of about 1995 standard rounds, the equivalent of 100 reloads, from full condition before breaking.
One of them can be found near Securitron de-construction plant on the pipe to the east from the main entrance. Just follow the pipe until you can find a spot which you can jump up onto the pipe.
The magnification level of the scope is 2.86x on this weapon.
Despite having the same ammo type and capacity as the Service Rifle, the Marksman carbine has a noticeably larger magazine (based on the 30-round STANAG magazine).
The weapon is based off a mix of the HK417 and the HK416, with the influence for the stock mainly taken from the HK417 Recon model and the rest of the gun taken off the HK416, namely the D10RS CQB model of the HK416.
Behind the scenes
According to J.E. Sawyer, the Marksman carbine is loosely based around "paratrooper-oriented marksman rifles" and are present due to New Vegas' proximity to Nellis AFB.[2]
One of them can be found near Securitron de-construction plant on the pipe to the east from the main entrance. Just follow the pipe until you can find a spot which you can jump up onto the pipe.
Marksman carbine with the extended magazine modification that was cut from the game
