Yup. F=MA. For every action there is an equal reaction.
It's the momentum(m*v) that results in recoil. Conservation of momentum means the gun must have the same momentum as the gas and lead lost. The lead carries a loy of momentum, but so does the hot gas. If the gun is heavier, it's speed will be proportionately less.
Chas... if you get a stock that has more of an angle than the original stock, it will reduce felt recoil. The reciever will sit higher when the guns sholdered.
Actually that's conservation of momentum.
Momentum is mass * velocity. For a given weight and velocity of shot the heavier the gun the lower it's opposite velocity will be. Of course it's not quite that simple, the force is indeed mass * acceleration, but acceleration is affected by the recoil pad, the way your particular shoulder "gives" and a host of other factors. Still, in general a heavier gun will produce less felt recoil for a given weight and velocity of projectile(s).