I believe this Snider barrel has be shortened from a "3-band rifle".
The front sight is mounted backwards. This would also explain the lack of a short rifle bayonet lug. There appears to be a rectangular area where the rear-sight base was soldered to the barrel.
The Brass barrel-bands and stock may be from European model 1853 Enfield muzzle-loading reproduction.
I imagine original bands would be steel!
My hunch is that your barrel has three rifling grooves instead of five.
p.s. A Snider-Enfield lock-plate should be flush with the wood. Your's is standing "proud".