There should be virtually no recoil force where the forend iron contacts the frame. The gun will of course recoil "Backwards", the tight grip on the forend would thus have a tendency to push it "Forward. If the lug solder gives then it will put forward pressure on the rib. pressure would not be exerted back into the frame nor on the portion of rib between the lug & breech.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra