Colt Model 1860 Army

[CowCavalry]

Seeing as how the force that would cause the wedge or slot to get battered loose would be in the opposite direction from the arbor, it seems to me that there isn't any particular good reason to have it bottom on the hole.
Having it bottom out would sort of defeat the principle of the wedge wouldn't it? It would be difficult for the wedge to actually draw tight if the barrel to frame assembly stopped short.

If I understand it correctly, the wedge was designed to keep the arbor bottomed in the hole in the barrel assembly?

 

[Old Soldier]

The wedge did it's job well. There are many stories and cries for help with a 'stuck wedge', especially in old, neglected pistols - as I know from experience. Often a wide punch or even a flat screwdriver is needed. Rust is excellent at 'fixing' moveable parts. BTW - the screw in the frame and the spring on the wedge are there to stop it falling out when pushed through, not to secure it.