The Viper Muzzle brake is a must have for your hunting and target shooting rifles.  Its been designed to reduce the maximum amount of felt recoil to allow the shooter to stay on target and to reduce shooter fatigue.  Test results on the Viper has shown that it will reduce the felt recoil on a 6.5 Creedmoor by 75% and on a 6.8 western 65% with more testing on bigger calibers to come!!
Viper Muzzle Brake Specs:
Material made from is: 416 SS
Weight:10.6 oz
length: 2.8 inches 
width:1.7 inches
height:1.4 inches
Coating: Armor Black Cerakote
AvailableThreads: 5/8-24 and 1/2-28
 Available Bore Diameters: .344, .295 and .250
.344 bore diameter can be used with all .30 caliber cartridges
.295 bore diameter can be used with all calibers 6.8mm or .268 diameter bullets or smaller. Please contact if you would like a 7mm size Diameter.
.250 bore diamter is for 5.56mm or .223 calibers or smaller
Comes with a Jam nut that is made in house in either 5/8-24 or 1/2-28
Please contact if you have any question on which size would  be right for your caliber.