I hate to slam a sponsor, but I cringe every time the Xtreme Hardcore Gear Slotted Muzzle Brake add appears on my screen. It is obvious that the folks at Xtreme Hardcore Gear figure that if a few slots work OK, a few more holes will work even better. So for the folks at Xtreme Hard core, a muzzle brake works by significantly reducing the contribution that the powder generated gas adds to the energy (Mass*Velocity*Velocity) that is INLINE with the barrel. It turns out that the gas has a significant mass and a REALLY significant Velocity. According to my old Sierra manual the gas is travelling at 4700ft/sec. (much faster than the bullet!!!) Which when you square it accounts for a lot of the energy down the barrel. By diverting a significant percentage of the gas out perpendicular to the barrel, one can significantly reduce the recoil contribution of the gas and signifantly reduce the recoil. If I start with a 13lbs 300wm rifle shooting 190gr bullets at 3017fps with 76.5gr of powder my perceived recoil is 21.21ftlbs. If I use a slotted brake and divert 75% of the gas to the side, leaving only 25% of gas inline with the barrel, my recoil drops to 10.72 ftlbs. I've cut the recoil in HALF!!! Now if I get drill happy and drill holes in the front of the brake, I might only reduce the inline muzzle gas by 65%. Those 6 extra holes at the front of the brake have reduced by recoil to 11.91 ftlbs. Those 6 extra holes just increased the recoil by 11%. At this point there is almost no need in going into the stupidity of placing top only holes on a brake...there is plenty of documented video online of the floated barrel slamming into the stock with that configuration.