I have no idea what recoil is like.
Depending on barrel length and the propellant, it may be pretty low for the size and mass of the gun and projectile, and not at all what you'd expect.
Recoil is a function of bullet mass and the rate of acceleration of that mass. Force forward is force backward. Whatever the level of force is imposed on the bullet is imposed on the breechbolt. Equal/opposite.
Look at it this way:
Hypothetically...Two handguns of equal caliber, equal weight, and firing bullets of equal mass.
One has a barrel length of 12 inches, and the other has a stubby 2-inch tube.
If you adjust the powder burn rate so that both guns produce the same muzzle velocity, the recoil produced in the shorter gun will be much sharper than in the longer one...because the rate of acceleration...forward and backward...is necessarily much higher in the shorter barrel. So, the recoil produced by the super gun in question may be more like a gradual, gentle, continuous push than the sudden, sharp "kick" that we understand as recoil.
Another analogy:
Accelerating a car to 60 mph in 3 seconds compared to accelerating the same car to 60 in 30 seconds. The 3-second trip is going to be breathtaking, while in the other one, the sense of acceleration will barely be noticed.