Musketoons can be either smoothbore or rifled. Musketoon basically refers to the gun as having a shorter barrel like a carbine version of a 3 band gun except that it only has two bands.
The Parker Hale 1858 two band musketoon has a 58 caliber, 24 inch barrel and is rifled with a 1 in 48" twist.
Parker Hale is a very reputable name and should be worth the price.

http://books.google.com/books?id=Dzx...20rate&f=false

Another musketoon with rifling is the 1861 Enfield Pattern Musketoon that also had a 1 in 48" twist.

http://en.wikipedia.org/wiki/Pattern...ield_Musketoon