Sherry, this is very interesting forensic research you are doing. Please continue to report on it. I hope to look at ordnance records for the 12th Missouri Cavalry one of these days when I'm at the Archives. All company records I have looked at so far indicate they had Starr carbines before June 1865 and Spencer's thereafter. The eight companies that went on the Powder River Expedition, I believe, would have all been armed with Spencer's because the regiment left a store of Spencer's at Ft. Leavenworth for the four companies that had not yet caught up with the regiment (one battalion was detached for service on Wilson's Raid through Alabama and Georgia). What model of Spencer carbine I can't say. We'll see what further research brings. Thanks. Tom Jones