The Longbow-DMR, boasting high damage per shot consistent to all ranges' is an ideal long range marksman rifle. Taking two shots to kill a Pilot, or one if it's a headshot (if the suppressor is used, it will take three body shots, and two headshots)
Being a Sniper rifle with the default 6x zoom, this weapon is at home on large, open maps with high vantage points and long sight lines. Finding a good vantage point to take advantage of this weapons strengths is key to success. Staying in position however, is not recommended as enemy Pilots will often close the gap on your location, and will likely engage you in combat situations you are ill equipped to counter. As such, the Cloak ability is highly recommended, as when your location is eventually compromised, you can Cloak and retreat to a safer position to resume providing sniper fire. If you prefer to engage enemies on the ground or in mid range combat, using the alternative sights such as the AOG sight or the 4.5x zoom is recommended, turning this weapon in to a high powered battle rifle of sorts. It is ill advised to use the suppressor for this weapon, as its damage is decreased considerably, taking an extra bullet to kill an enemy Pilot. Though your gun shots won't show on the radar, the semi automatic nature of the weapon and its slow rate of fire (compared to the other pilot weapons) means that your time to kill will be extremely compromised.
After you get a few shots out, it is recommended to Cloak and relocate. If you don't have a silencer, they will come chasing you, so if you relocate and they look for you, you can get a free kill.
The AOG, or Advanced Optical Gunsight, is fixed at 2.4X magnification, and includes an integrated “current magazine capacity” readout with a backup numerical display. The AOG is ideal for combat at extended range.
Not having to lead your shots makes this weapon strong for cross-map sniping of moving targets. This is not a run-and-gun type of weapon; find the best locations to set yourself up to pick off enemies from a distance.
If the enemy Pilot is not moving, take the extra second to line up the headshot to guarantee the kill. Otherwise don’t be afraid to miss a shot on a moving Pilot. This sniper rifle has a rapid rate of fire that you need to take advantage of because it takes two body shots to kill a Pilot.
If you don’t have the Suppressor equipped, you have to shoot the AI and then relocate to avoid enemy Pilots that will sneak up to your location. Otherwise, this weapon is fast at picking off a group of AI at a distance.
When backing up your teammates, the Extended Magazine is a great way to have four more rounds in your magazine to give extra cover fire. When in doubt, use the Suppressor; it will allow you the opportunity to miss a few shots without giving away your position to the entire enemy team.
Should you find a suitable sniper's nest, it is recommended that you place Arc Mines in strategic points around your position, to help ward off Pilots that may come from behind. While this won't help with your aim or your use of weapons in general, if somebody comes in for an execution, at least you'll have a fighting chance.
Arc Grenades are recommended if you have the AOG scope, and Arc Mines are recommended for the 4.5 zoom scope, as the 4.5 zoom scope struggles for close range combat. So if you find yourself in a close range fight with a 4.5x scope, you can throw a bunch of Arc Mines and have a chance of killing the enemy.
The hypervelocity rounds fired from this weapon leave vapor streaks in the air when fired, which look like faint white lines. Experienced players can trace the streaks back to the sniper, even with a suppressor attached. After firing a few rounds, it is a good idea to relocate regardless if a suppressor is equipped.
The DMR, presumably a continuation of the Longbow-DMR Sniper, reappears in Titanfall 2 with a reduced magazine capacity of six. Presumably, this was to further separate its role from that of the G2A5 rifle, and prevent players from seeing it as a comparable battle rifle.