Thank you Daryl, That clarifies it for me . Bore and Gauge are really different terms for the same thing. At any rate a 12 pound gun is way too heavy. One question why do you use bore for some guns and caliber for others? I don't believe I've ever seen you call a .50 cal rifle a 35 bore.
Very often this was so, Bill. There was some interchangeability, though, through the 1850's onwards.
Way back when - the standard English language for guns was all by the "bore" or as we call it "gauge".
Normally in the states before and after the revolution, gun calibres were called by "# of balls to the pound"- other words for that "phrase" are bore and gauge.
The two books I have encouraged the guys here to obtain, "Firearms of the American West" - both volumes - have many re-printed "orders" from stores and from outfitters in the West, ordering rifles, smoothbore and smooth-rifles, as 180 to the pound, for .29/.30calibre rifles, 53 to the pound, for .44 to .45 calibres, 32 to the pound for .52 or .53 calibre, then of course, for larger calibres, more common to us, 20, 16 , 12 to the pound or bore.
I mix up the designation of my big rifle, calling it either a 14 bore or .69 - depends on just what I happen to call it - I use both even though a true 14 bore's measurement land to land is .693" & my rifle is .003" smaller than that. That too, was common - in the 1800's. Also common was the use of one 'gauge' or 'bore' smaller in ball size. So a 14 bore (.69) would use a 15 bore (.677) ball and a substantial patch to take the rifling.
Interestingly enough, the American Mil. Muskets of the 1700's (following the French designs) on up to 1842, the first percussion Musket were called .69's, not 14 bore. Too, these would range from just under .69, right up to .70 cal. before more tightly controlled dimensions were ordered (around 1809- I think) for interchangeability of parts, etc.
A .50 would be closer to a 37 bore, which has a .501" bore size & would likely use, back then, a 40 bore, ball, around .488" or so.
What really confuses the issue was after the change to ctgs. wherein the groove diameter was used in the name - generally, while others continued to use the bore size as in England mostly but not exclusively. It all can be confusing.