Arma 3: Marksmen Review (RoboGen123)
This DLC adds:
MK-I EBR and Mk14 7.62mm marksman rifles. Use these if you are your squad's marksman, they kill with 2 rounds at most ranges and are fairly light, especially compared to other DMRs that fire bigger ammo. They are far more versatile than the high-caliber DMRs since they can be fired full auto at close range. Also, the Mk-I EBR is the most accurate 7.62 DMR.
MAR-10 (.338 Lapua Magnum) and Cyrus 9.3mm sniper rifles. Both are meant for ranges of around 800-1500m, they pack a big punch, will likely kill in one shot and are semi-automatic, and can be suppressed. Great for wiping out squads of unsuspecting enemies quickly.
ASP-1 Kir short-range suppressed special-purpose rifle. Fires a BIG 12.7mm round at a subsonic velocity, making it extremely quiet but it has a very low velocity and should be used only below 350m, also make sure you use its dedicated scope that can make precise adjustments in increments of 25 meters.
SPMG .338 and Navid 9.3 machine guns. They pack a big punch, have a very long range and can easily shred MRAPs and lighter helis, but they and their ammo is very heavy.
Kahlia and AMS marksman scopes. They bridge the gap between the low-power DMS/MOS scopes and the high-power LRPS scope.
Full Ghillie suits which have reduced visibility on thermal scopes, and a remote controlled laser designator.
However, there is plenty of free marksman gear in the base game:
Rahim and Mk18 ABR 7.62mm marksman rifles (Rahim is the lightest DMR in the game at only 100 mass units, though it has a very limited magazine size of only 10 rounds)
M320 LRR rifle, the most accurate sniper rifle in the game and can kill enemies in one shot even at 2 kilometers
GM6 Lynx rifle, it can fire very powerful 12.7mm (.50") APDS rounds that can easily penetrate MRAPs, as well as killing people with L5 armor in one shot at any range, and is semi-automatic, but less accurate than M320. If you are looking for a massive long range machine of death, look no further.
DMS and MOS marksman scopes. They have a 4-5x zoom, suitable for 7.62mm DMRs.
LRPS sniper scope (best zoom in game at 25x), Rangefinder, standard Ghillie suits, bipods (yes, all of them are free)
So if you want to just try sniping you have good equipment already available, id recommend this DLC to people who take sniping seriously and want highly specialized gear for the job.