John in NM
The rails won't help any because the "nut" portion slides in them. Now if they were rigidly attached to either the front bushing or the theoretical plate that Bob was proposing, they would contribute.

However, I do agree that for all but the most extreme abuse (see my "breaking of my wetzler clamp" for what I call extreme ) the cap/bolt arraignment will be fine. I would have no qualms about using it that way personally, even if it is not theoretically as strong as other methods.