Originally Posted by SKI008
They are a heavier pillow bolt. Basically heavier bolt means you have more mass to smack the valve open with so you can run at a lower LPR and slow the bolt speed down for less kick.
Or something like that.
They are actually the same weight as the stock bolt. The heavier weight was a misconception when the bolt was released. The bolt's body design is the same as the stock dirt resistance bolt (a good thing), they have a new pin design but can be purchased with the standard, there is now an aluminum insert that contains the pillow. In comparison to the old pillow bolt I have noticed a little bit of a FPS gain and some improved consistency at a lower lpr setting. I largely contribute this to the slightly tighter fit of the the bolt. There is supposed to be an improved air inlet on the bolt but in my inspection I haven't been able to find anything different from the stock inlet.