Sideclips were invented to address the twisting moment caused by the barrel being fired's position adjacent to the centerline of the shotgun. Every shot produces this twist, eats at the pin ( most commonly on the side fired first), and shortens longevity. In the early days, metallurgy wasn't as advanced as today, and consequently beefier surfaces were a common attempt at slowing wear.
The sideclip acts as a lever to the axis of rotation about the pin, and as it is a long radius away from the point of twist, adds considerable resistance to twisting. Just ask Archimedes.
I have read this repeatedly, seen it posted here and elsewhere, and am quite surprised no one tossed this in 3 pages ago.
Get with it lads, use your A game!
