Hi all, I am curious on how how this breech block locking mechanism works in this action? Would anyone have any pictures of original parts or can take pictures showing this parts function? Remember this is different from the type 1 action. 


Part highlighted in red. 

In all the decades I've been attracted to Remington single shot rifles the early split breech have been elusive, and I rarely see them at all. I was hopeful when Marcot did his book on Rolling Block rifles that he would cover them, but not even a mention of them.
Of course they were all originally rimfire rifles, but in the early stages of the Civil War many were converted to CF .58 caliber, and .50-70 caliber. I can see how the RF version would work with a split breech, but never seen the conversions and no idea how they accomplished the conversion to CF with this design?
From pictures I've seen of Split Breech Remingtons it appears they were all carbines. At least I've never seen a rifle version.
 
The part circled in red appears to be either an interlock to prevent firing with the breech block not fully closed. Or it may be part of the extractor system? Just not familiar enough myself.

A better sized photo.

I agree with stopping the trigger, it looks like the tab on the trigger spring either lays under that part or goes through that hole and when it is depressed it would stop the trigger movement. If you look at the other picture I posted you can see the interlocking cams on the hammer and the breech block, without the breech block fully closed the hammer can’t engage or engage enough to make more then a few degree rotation.

marlinguy wrote on Nov 13^th, 2018 at 12:13pm:

Not likely converted during the Civil War as the Berdan primer was invented in 1866 and not perfected until 1867. The Boxer primer was patented in 1868. The .50/70 appears to derive from the Joslyn rimfire and attempts to convert in 1866.