The Cook Brothers as well as the Enfield Musketoon Pattern 1861 from Pedersoli, both have 24" barrels but they are rifled. They are a tad too expensive to then have them reamed....
The flintlock French An IX de Cavallerie from Pedersoli has a 30" smoothbore barrel, and if you don't care about having a bayonet, you could probably go to 26" with ease.
LD
Not sure if your agreeing or dis-agreeing but either way it Just goes to show there are many muzzleloaders both smooth and rifled barrels less of than 30 inches prior to 1919, as you stated in post #55
heck Im looking at a few in my safe right now.
I believe it was Macon Armory that also produced an 1842 smoothbore carbine with barrel of 20 inches or less, held by a single band and its tang screw. This was made from salvaged (rased) and battle damaged 1842s
And again I have an Austrian Frunwirth with a factory 13inch barrel.
Although not common, short barrels are far from rare. Factory made, blunderbuss, cut downs, rased barrels, canoe gun, blanket gun....they go by many many different names throughout history, but they are there and were not rare.
No reason why one cannot have a shorter barrel and still be correct!
I personally own an 1861 Springfield that has had its barrel cut to be a Richmond Musketoon as documented in the book Confederate Carbines & Musketoons by John M. Murphy; Chapter XIV Macon & Richmond Armories Alteration of Muskets for Cavalry Service; pages 166 to 175
The book is an excellent read with many smoothbore and rifled bore arms