I use the FAL pretty extensively and noticed something in game while using it and decided to start a test session to see if I was right. And I was. It has to deal with the attachments regarding the FAL. I used the RDS, holo sight, ACOG sight, grenade launcher, and silencer.
With no attachment: Virtually no recoil.
With RDS: Little to medium recoil.
With Holo: Medium to high recoil.
With ACOG: Medium to high recoil.
With GL: Little to medium recoil.
With Silencer: Virtually no recoil.
This may or not be true. But I used OMA (One Man Army) for the six classes and shot all the bullets as fast as possible. I looked at the bullet spread and from that, I was able to determine the recoil. Now obviously this only comes in to play if you have a quick trigger finger. If you treat it like a sniper, only taking one shot, then it will have no recoil regardless of the attachment. Just thought I'd share the info.