Frame cracking after rail installed

[Fdisk]

Ive read a few time where the frame of a 1911 will crack in time if it has been driled taped for a light rail.
Is this realy a problem i cant see the dust cover being under that much stress.

[Jolly Rogers]

Frames have cracked on 1911s in the area of the dust cover in front of the slide stop hole without any additional weight of added light rails. The action of the firing cycle and inertia stresses the frame there and the flex can cause cracks.
Joe