I think many people miss the point about bushing firing pins.

It is done to prevent gas escape from blown primers!

If a firing pin and associated hole in the breech-face are too large, the pressure from firing will push the firing-pin back and the primer will expand into the hole, either locking the gun closed, or in extreme cases rupturing and blowing gas into the action as per the Ellis Brown example. If the firing pins are correctly bushed, using modern reloading components, there will be no escaping gas to redirect!

The old Scott patents for gas-ports in the breech-face were 'invented' at a time of black powder, corrosive primers, weak metal alloys, and questionable reloading practices in the colonies. There is no need for them today, which is why no contemporary maker gives them a second thought.