The two little bumps at the end of the stock that apply slight upward pressure on the barrel.
In theory and in practice, they calm a thin barrel down by dampening the harmonics (or the whip) as the bullet travels down the barrel.
Some people report better accuracy by removing them and free floating the barrel (no parts touching the stock forward of the barrel shank).
I have 3 T3 Lites, all with intact speed bumps. The worst is a .308 that shoots 0.8" to 1.0" at 100 yards. I'm not messing with them, but I have a question for you guys that do.
With the speed bumps removed, can you squeeze the barrel and forearm tip and produce contact? One of Mule Deer's observations is if you can get contact, more material must be removed.