Now that we've covered the basics in Recoil 101, lets go further and look into how muzzlebrakes reduce (not eliminate) recoil. An efficient muzzlebrake will have an arrangement of ports and baffles to stop the forward movement of propellant gases and divert them at a perpendicular or rearward vector away from the direction the bullet is travelling. Stopping the gases creates deceleration forces that counteract the initial forces generated by accelerating the propellant mass. Although there are some other small variables and such, we're going to go back to our previous equation and start factoring in the muzzlebrake changes. ma[rifle]=ma[bullet]+ma[prop]+.25m(1.25)a[prop 2nd] If the muzzlebrake baffles can completely stop 75% of the propellant then we will counter approximately 75% of the primary force incurred accelerating the propellant, so our new equation will be close to this: ma[rifle]=ma[bullet]+ma[prop]+.25 m(1.25)a[prop 2nd]-.75 ma[prop] If the ports can divert that same 75% laterally away from the bore, then the equation will now be something close to this: ma[rifle]=ma[bullet]+ma[prop]+.25 m(1.25)a[prop 2nd]-.75 ma [prop]-.1875 m(1.25)a[prop 2nd] If we punch our previous values in for the 49,000gr rifle, 150gr bullet, and 50gr propellant charge, we get the following: 49,000a=15000+5000+1562.5-3750-1171.9 49,000a=16640.6 a=.340