that is actually a new product called the "squid-brake". the "squid-brake" is a new design of muzzle brake that helps to disperse the gasses in the normal left to right manner, but also disperses them up and down, which completely eliminates muzzle flip, and also greatly reduces felt recoil.
this is the first i have seen a "squid-brake" on a ruger. every other one ive seen has been on the remington 700 series rifles.