Ron,
The .69s were used alot more than most people think. I have returns from the 33rd Miss. Inf from July 1864, where they are turning in .69 muskets and cartridges due to "want of transportation" They seemed to be trying to standardize to .577/.58 cal as the .58 stuff was marked thru.
Next dedication we do together, I'll load up some buck and ball and let you shoot my 1838 Springfield.
Working on the Thompson stuff you sent.

Virgil