The Hawken Bros. would presumably make any length you wanted so it's possible. When I had mine built I was going by references from a book on Hawken rifles. I believe it was The Hawken Rifle, It's Place In History but it's been a long time since I've seen it and not sure where it got off to. Anyway it stated that barrels ran from 33-40 inches. Since then I've learned of shorter ones, as short as 30 inches but don't know if they were thought to have been cut.
I blatantly stole this post from another forum.
Jim Gordon in his book "Great Gunmakers for the Early West" Vol III says of barrels: "...lengths range from 30 to 40 inches with the majority being 34 to 36 inches". John Baird in his book "Hawken Rifle, the Mountain Man's Choice" shows photos of seven original Hawken rifles, whose barrel lengths I scaled out based on a 5" lock. Lengths were 32 1/2", 33", 33", 34", 34", 31 1/4" and 30 1/2". These calculations are likely not exact but very close. And that short one had a checkered pistol grip stock, a heavy barrel and a base for a tang mounted peep sight. I have seen photos of at least two more similar but longer barreled Hawkens. Shumway's Longrifle Articles Volume II page 158 has photos of an original J&S Hawken of .49 caliber, checkered walnut stock with a trigger reach of 14 1/2", one key, 30 3/4" long barrel, with charcoal blued iron butt plate, toe plate and trigger guard but all the rest of the furniture German silver. The butt plate is 4 21/32" high and 1 9/32" wide. A writer named Tag Rittel wrote in Buckskin Report (I think it was) of a Hawken he built with a short barrel for use on horseback hunting. I think it was 28". Probably would take me a couple of days to find this article, perhaps someone else has it. Here are original Hawkens in Jim Gordon's museums. I scaled that shorter one fifth down at about a 30" barrel.
Note that only one of them appears to have a patchbox.
