Wow they must have changed something because my Hart brake didn't do that much on my Sendero in 300ultra. I actually had to mill further into the break just even with the furthest side of the the first set of holes to get it to work better. I did this to make it more like the KDF unit that works much better. At 85% a 300ultra would shoot like a 22lr.
i had HART give a sendero the works.the muzzle brake they said would reduce the recoil by 45 % they were wrong it's like 85 %.best break and work i ever seen and fast under 30 days after i sent the gun in,thanks,keith