Ron,

Wasn't the "James rifle" name also attached to a number of 3.67" bronze rifles that had not been reamed to 3.8"? These 3.67" rifles also fired James ammunition. Contemporary nomenclature was haphazard, with the 3.67" versions considered 12-pounder rifles, while 3.8" were 14-pounder James rifles. Confuses the heck out of me and I'm still not sure that there is any crisp dividing line.

(Of course there were heavier guns rifled for James projectiles, but they weren't army field pieces like the ones we are discussing.)

3.5" rifles would be Blakely's most likely, but of course these wouldn't have been in Federal hands at Shiloh.

Stones River has a few varieties of James Rifles as well.