Ran into this bug while comparing the bullet velocity and drop of a few sniper rifles on PC.

If you equip your weapon with the "Standard Muzzle" attachment in the Gunsmith Menu and then apply a Suppressor to your weapon while aiming, your bullets will maintain non-suppressed bullet velocity.

It is only when you select "Suppressor" in the Gunsmith Menu that your bullet velocity is hindered when shooting.

Let me know if anyone can reproduce this and hopefully it can get fixed soon. Suppressors are feeling a bit overpowered to me right now with this bug.

EDIT: I forgot to mention that this seems to apply to all weapons that have a suppressor option.

EDIT 2: It would also seem that the opposite is also true. If you apply a Suppressor to your weapon in the Gunsmith Menu and then remove it while aiming, your weapon will maintain the same bullet velocity as if it had a Suppressor equipped.