This is a common question I see popping up on various forums and there is a very easy explanation when it comes to attachment selection.
A weapons primary attribute is the most important factor when selecting the best attachment.
The primary attribute is the strongest point of a weapon. Listed below are the general attributes for each weapon family. These are guidelines only and some weapon classes have multiple niches. For instance the PDWs like the P90, PDW-R, MP7 etc are excellent when hip fired. The shotguns are good at close range and the assault rifles are better when aiming down the sights. Some of the more popular weapons are listed below with their specific benefits alongside. Keep the strong points in mind when selecting your attachments in order to further accentuate the strengths for a better weapon, rather than creating a more rounded weapon.
This article assumes the reader has mastered, or at the very least is aware of concepts such as recoil control and when/when not to aim down sights. Also basic gun mechanics are handy to know.
Basic gun mechanics
There are two main gun mechanics at play in BF3.
Recoil – the kick when a weapon is fired that causes the users aim to ride up. Can be controlled by gently aiming down to counteract recoil
Spread – Random deviation applied to every bullet that leaves the gun. This is applied to the first bullet and what causes the first bullet to not perfectly hit where it is aimed.
Both these values are increased by firing while moving and suppression. Standing gives the highest amount of each from the three stances (stand/crouch/prone) but crouch is not a large enough improvement over standing to bother using it. Prone is a decent step up and worth using if the situation seems appropriate. What is not appropriate is dolphin diving, the time between going prone and being able to fire effectively is too long.
Sorry about the weapon mechanics 101.
Battlefield 3 Attachments
This is the point where we go over the attachments and their specific mechanics.
Heavy Barrel reduces spread when aiming down sights, increases vertical recoil and decreases bullet falloff. It also has a small amount of extra recoil when hip firing. These weapon changes basically mean that your weapons are much more on target when ADS firing.
A heavy barrel gives greater accuracy for aimed fire, but increases the toal vertical muzzle climb due to the use of heavy match ammunition. Match rounds do not increase the overall damage of the weapon.
Laser Sight removes spread when hip firing. Has no benefits beyond that. The main drawback is the laser can be seen. It can be turned on and off.
The laser sight adds a visible laser aiming dot to the weapon which increases accuracy from the hip. The laser sight can dazzle enemies when turned on, but also reveals your position.
Flash Suppressor reduces vertical recoil when aiming. Adds extra recoil or spread or something when hip firing. The amount of recoil it reduces is quite large – however it does nothing for your spread. This means that your first shot still has the weapons default amount of spread, which is really unacceptable and inaccurate.
The flash suppressor hides muzzle flash but will not hide the player on the minimap. It also acts as a compensator, decreasing vertical recoil but reducing accuracy from the hip due to their additional weight.
Suppressor removes your arrow from the mini map when shooting. It also lowers spread. However it increases bullet drop off, causing your weapon to deal less damage. While this attachment was quite popular in the original release of Battlefield 3 it is outclassed by heavy barrel in its current iteration.
A sound suppressor will prevent the player from showing on the minimap when shooting by reducing sound and flash. The cold loaded ammo used by suppressed weapons travels slower and has a shorter range.
Flashlight is used to blind players. Is not overly useful and does not affect weapons beyond not being able to utilise a more useful attachment in its slot.
A tactical light lights up the dark environments with white light. In close quarters the tactical light can also disorient and temporarily blind others, but can also reveal your position.
Foregrip adds some spread and reduces recoil when hip firing. The foregrip has a small amount of extra recoil when ADS shooting.
A foregrip decreases the amount of horizontal muzzle drift when firing a weapon, giving better control overlong bursts. Vertical muzzle climb is unchanged and long range fire is less accurate.
Bi-Pod reduces spread and recoil to laserbeam proportions when deployed. Downsides? You have to deploy it and is rather clunky to use a result. For weapons where the foregrip is not useful players may like to take a bi-pod in its slot for the occasional utility it may provide. I would suggest rebinding your bi-pod deploy key if you opt to do this as having it on fire can slow down ADS when prone and get you killed.
The bipod can be attached to light machine guns (LMG), sniper rifles, assault rifles and carbines. It cannot be attached to the AKS-74u, G53, QBZ-95B or A-91.
Bipods allow the shooter to support their gun on flat horizontal surfaces, or when prone, to gain an increased accuracy and reduced recoil.
Optic attachments are covered in another article here.
Assault Rifle Attachments; Assault Attachments
Assault rifles in Battlefield 3 are primarily used ADS. They are effective to medium range by default and with the correct attachments effective to mid-long, even useful at long range in a pinch. Some assault rifles excel at close range and some are more effective at longer distance. Effective range really comes down to rate of fire – the higher rate of fire weapons such as the AEK-971, FAMAS and F2000 are more effective at close range due to the larger number of bullets possibly hitting the target on full automatic. These weapons are not overly effective at long range because their recoil and spread are too high. Of the three the AEK is the more rounded weapon and is at least usable at longer range, whereas the F2000 and FAMAS becomes rather useless and spreadtastic at around +30m.
The top 5 assault rifles based on popularity in BF3 are: M16 (M16A3), AEK-971, M416, F2000 and AK-74M.
All the assault rifles hip fire passably well, but like carbines players are probably better off aiming down sights at ranges over 5m. Even in closer ADS is advised if you are in control of the situation. This means if you are dictating the fight (or camping) and you are aiming the corners, you should be aiming rather than hip firing.
Since ADS is the primary attribute, the usage which the assault rifles excel at, the first attachment to pick is the heavy barrel. HB turns the assault rifles into almost pinpoint accurate killing machines. Most players will run the heavy barrel almost exclusively. This is because it removes a large amount of spread and the first bullet hit area is very close to the crosshair when aiming. Drawbacks from the heavy barrel; recoil is generally able to be compensated through aim while bursting and players generally live with the hipfire penalty because hipfire is not the prevalent use of the weapons.
The best attachment for assault rifles is the heavy barrel. As of the Close Quarters patch there is no discussion really. The suppressor is useful for its ability to hide players on the mini map, but the CQ patch totally killed damage at any sort of range. Apparently this may be fixed in future patches.
Laser sight for assault rifles is generally not useful as players do not hip fire them often. One exception may be the FAMAS which is apparently almost as useful as the PDWs when hip firing with a laser. However the weapon is pretty useless with a normal load out of assault rifle attachments.
Flash supressor is an interesting guy. At first glance he seems as useful as the heavy barrel. He removes quite a substantial chunk of recoil, making assault rifles more controllable. This is good. However once you realise that it does nothing to the first shot you understand how useless it is. The “hit area” is still large and spread is still a major pain in the ass.
Should I use a foregrip on my assault rifle. The short answer is; no, you should not. Unless you are running an AEK-971. Even with heavy barrel the weapon negatives do not outweight the positives on any gun except the AEK. More detail can be found here. The short version is that the foregrip changes each weapon differently and the only one that is enough to not be totally detrimental is the AEK.
The last attachment for assault rifles is the bi-pod. The Bi-pod is not really intended for use on ARs in Battlefield 3, however since you probably do not want a foregrip the bipod may add some utility now and then, unless of course you use underslung.
I like bipod when defending a very specific area; for instance tiles on bazaar. Besides this sort of scenario its not very useful, and can have a negative impact to your game if you leave the deploy bind on your ADS key. Rebind that asap!
Carbine Attachments; Engineer Attachments
Carbines in Battlefield 3 behave similarly to assault rifles. They are slightly faster when aiming down sights and their dropoff is shorter due to being lower powered. Per bullet damage is slightly less across the board, however at close to medium range this would at most be one extra bullet on target compared to an AR.
The top 5 carbines based on popularity in BF3 are: M4A1, G36C, A91, SCAR-H and AKS-74U.
Attachment wise carbines are the same as the assault rifles, however to my knowledge you do not want to ever run a foregrip on these guns. For carbines you should pick heavy barrel and rail/bipod. Again the heavy barrel provides superior spread reduction when ADS.
Light Machinegun LMG Attachments; Support attachments
I don’t know what to say about support players, I am personally not a huge fan as assault and engineer seem more useful, but many players opt for support with their hulking LMG and explosives.
The top 5 LMGs based on popularity in Battlefield 3 are: M249, PKP, M27, MG36 and RPK.
First and foremost I think the LMGs are generally fairly unreliable. First up there is no option for a heavy barrel so you get to play with the massively inaccurate default spread. Next up they all kick like rabid bulls and controlling the recoil is a total joke. If you are incapable of aiming you might be able to get by spraying and praying, sometimes.
For barrel attachments you can select from the flash suppressor or the suppressor. The suppressor suffers from the same drawbacks when used with the assault rifles and carbines; major bullet drop and damage reduction. The flash suppressor helps control recoil somewhat and is probably most players best option. If hipfire is important then taking no attachment would be the best route.
DICE intend the LMGs to be a setup weapon using bipods. In reality it does not work very well and you are easily killed by any semi competent players. I have had awesome rounds playing with the bipod, but I have had equally shocking rounds where I am picked off because of my stationary nature. Perhaps it is just how I play but I would say go for a shotgun or PDW (if you want an assault rifle the AS VAL is the closest available) over an LMG.
Sniper rifle attachments; Recon attachments
Lastly we will look at sniper rifle attachments. Choice is here limited similarly to the light machine guys. Sniper rifles can take the laser sight, flash suppressor(semi auto only), suppressor, bipod, straight pull bolt(bolt action only) and foregrip (semi auto only). Rifles are decent straight up and you could slap a sight, and straight pull if using bolt action on one and go from there. The other attachments are not overly useful. If you are playing aggressive recon with the SKS a laser sight might be useful for hip firing at close range, but you will probably get outclassed by most other guns.
Going the long distance sniper route means you cannot take the suppressor as the drop off is such a killer. The bipod does nothing for bolt actions because there is no kick between shots like with all the other weapons.
Foregrip is not overly useful for the semi auto rifles because the horizontal kick is fairly non-existent.
Take a scope and a straight pull. Add a taclight for annoyance.
Whaat. So what is the best attachement?
The start of the article mentioned that the weapons primary benefit should be focused on when selecting attachments. Keep you weapon of choices key good points in mind when selecting your attachments and you won’t go wrong.