1855 vs 1861 Springfield hammers

[Groatski]

It's always been my assumption that the 1861 Springfield is simply an 1855 Springfield with the Maynard tape system removed - all other parts being identical. However in Claude Fuller's book 'Springfield Shoulder Arms 1795-1865' there's a list on pages 118-119 listing the interchangeability of components between all the Springfield rifles between 1855 and 1873, and the hammer of the 1855 are listed as being different from the 1861. What changed? They look exactly the same. In fact I always thought the distinctive arch of the 1861's hammer was to get around the now nonexistent hump of the 1855's Maynard system.

Anyone got any ideas on this?

 

[Jobe Holiday]

The Model 1855 hammer has a tape cutter on the bottom edge of the face of the hammer. The Model 1861 has a full cup closed at the bottom edge.

 

[Craig L Barry]

Jobe hit it on the head, but the hammers will actually interchange. In other words, a 1855 hammer will work with a US 1861 lock and vice-versa, as long as you aren't using the tape primer system. They are the same dimensions and appearance except for the notched "cutter." Kind of a fine point, but Fuller isn't wrong saying they don't interchange it's just kind of misleading. They will both work fine in terms of functionality if you are using percussion caps, as they did in the US Civil War.