Trapdoor Rifles

There was recent discussion on a trapdoor with enigmatic "E" on the breech block.

Here is another one, which IIRC looks about the same. It is on an "assembled" Metcalfe rifle in upcoming RIA auction.
https://www.rockislandauction.com/detai ... lfe-device

Thanks for finding this John. Yes, it does look like the same style font and size E that’s on my early 1873 rifle, and it’s in the same location on top of the Breech block.
Very interesting.