The correct perspective
Flatline is indeed a terrible idea, for several reasons.
1. It can't hit crap at the distances you think you're buying it for anyway.
2. It actually slows the ball down so it doesn't break at back player ranges.
3. Tis a pain in the arse to clean.
4. Adds weight and length to the gun, making you more of a target.
5. Is unnecessarily expensive.
In short, it's a crappy idea that shouldn't even be out there in the first place. It's just a stupid gimmick made to take money from ill informed newbies. And as my collegues have pointed out, there is no such thing as "snipering," attempts at which are more adequately described in paintball terms is lack of aggression, inadequate forward play, and misunderstanding of paintgun function and tactics.
Instead, the proper attitude towards back play is this:
1. Be able to pour out paint quickly and accurately from as long a distance as your marker and barrel will allow. There is no "sniping," implying single precise shots from two or three times outside the range of opponents--the notion of such is rubbish. Accurate and fragile paint, well made and fitted barrel, and consistent firing low pressure guns like Shockers and good Cockers extend effective (accurate and sufficient velocity) by about 10 feet. Even from there, paint is not a perfect projectile, so rather than counting on one shot to be perfect and be the elimination of your opponent immediately, you coordinate strings of fire towards opponents that cover the area which likely they will be in when they impact. Unlike shooting a rifle where the time between the bullet leaving the barrel and its impact is negligible, your opponent is moving a bit while your paint is in the air and can significantly impact the probability of a hit. Hence like a high speed camera, you take several shots rapidly to catch them perfectly with at least one out of a probably imperfect 5-8, compensating for your error, the paint's imperfections, and the person's movements all at once. The fact that you have a better marker, barrel, and paint for the task means that you are more likely to succeed in taking advantage of the moments that they give you to shoot them at the given distance than they are with you.
2. Be able to direct front players' movements. Your position as a back player means that for the majority of the game you are able to look around more than your front people that are taking a lot of paint due to their closer proximity and usually smaller bunkers. They need to know from you when targets are nearby and present themselves for easy shots, as they themselves cannot be looking as often for fear of overexposure that can be taken advantage of at short range. They need to know when and where to move up to pinch in on the opponent's position, as that is their job. They need notification of and protection from bunkerings (muggings in English English)--if you can see someone coming up on them, you yell it to them as to which side they're coming from while doing your best to shoot the aggressor yourself. There will ALWAYS be a member of the opposite team sticking up, moving, podding, or walking off dead, all of which are events your front players need to be aware of and cannot necessarily see from their position. If you have no news of the opposition, call out the time remaining, teammates remaining (in some kind of code, as to not inform the enemy of their success rate if they haven't kept good count and might be under/overestimating you, which works to your advantage if they are), encouragement to your team, or insults to the other.
3. Constantly be shooting and/or talking. NEVER SPEND ANY PERIOD OF TIME LONGER THAN 4 SECONDS THROUGH THE ENTIRE GAME NOT TALKING OR SHOOTING... It is your job to be doing both at once, all the time, with as few interruptions as possible. Keep giving your forwards the confidence that you are still alive and on top of things, and laying out enough cover paint for them to walk on and relevant and timely info for them to win on. Any sticking out or movement of the opponents you should shoot at. The goal is to maximize your odds of eliminating them and minimize their chances of successful movement and observation of your forwards' movements.
4. Set the tone of the game. Off the break, rather than immediately scrambling for cover, you should attempt to shoot out as many of the opposition running for their bunkers as you can before needing to avoid the paint they will eventually send at you. You can either shoot at the opposing back players who will likewise be primarily occupied with shooting at your forwards and exposing themselves or take out their forwards to contain their team as a whole and open up room for advancement of your forwards. Ideally you do some of both. To take out forwards, you use sweetspotting: instead of shooting at where they are presently, you shoot right near their objective bunker where they will no doubt cross through and moving more slowly than the rest of their run. This either negates their attempts to take important front bunkers or deters them from trying, giving them less of the field to call their own and more of it yours within seconds of the game starting. In this and your relentless hailstorm of paint at long ranges throughout the game should establish a sense of dominance--the other team is NOT allowed to move, and YOU should be the reason they can't. They should be pissed off that you're still there, putting paint on every inch of space they try to take, giving away their every move, and insulting them as far as non-penalty deserving trashtalking will allow to utterly infuriate and humiliate them. They should be trying to shoot at you all game at any cost because they don't want you there because you doing your job keeps them from doing theirs. Because the opposition is putting all their attention on you, because if they don't they're out, then your forwards and mids should have as little opposition as possible marching right up on them to put them out. Success is when your team makes their moves swiftly and without fear because they see you're doing what they need you there to do.
