I am still considering building a rifle with a very slow twist rate barrel for hunting with roundballs as was suggested here. Thinking about a 1:106 or 108 rate of rotation in a 36 inch to 40 inch .58 caliber tapered barrel. The main concern is the recoil it would have. Ive considered fowlers with a rifled barrrel, various muskets like the early version of the Baker rifle or 1803 musket, early Lancaster or Virginia or Clark rifles and even underhammer style on a shotgun stock. I am fond of fullstocks particularly Jaegers or transitional rifles like the Edward Marshall rifle. My question is this... Would an octagon to round tapered barrel or tapered unflared octagon barrel be too historically incorrect for a Jaeger or transitional rifle? I thought about a style similar to the Pedersoli Mortimer also. These are hallfstock but could be made to except an interchangeable shotgun barrel.

Thought about buildiing an underhammer like the Pacific Arm rifles using the staiinless steel trigger and lock they offer at the Blue Grouse website but it looks to me that such a getup would break buttstocks. Dont know if these locks would be very fast since they look so simple to me either. One good thing about a half stock is that English wallnut or other expensive wood would be cheaper in smaller chunks. Also wondered if a hooked breech on an sidelock English sporting rifle would not be a good idea because maybe it would get off kilter with heavy recoil eventually and cause problems. I am just playing around with options again. Dont mind me.

Oct-rnd will be out of place on the Jeager style, strait octagon would be the way to go.

1:72 is a good all-around twist for the .58 & .62, it'll allow you to stoke them up for hunting and turn them down for punching paper so as to not beat you up. The 279-286gr ball in the .58 isn't going to run out of horsepower in 1:72 within its acceptable deployment range for hunting. The real slow twists are more important in the .62+ bore but only if you plan on pushing the range to the maximum or you're going after something in the "big five" catagory. In .62 & smaller bores, the 1:72 is alot more versatile and you aren't giving up anything when it comes to normal hunting conditions. Maybe some of my posts were a little confusing - when you get slower than about 1:80 on the twist, you're into a dedicated heavy load special purpose only rifle. The bigger the ball, the heavier the load, the more punishing it becomes to shoot and if you plan on shooting enough to be proficient with the rifle as a general purpose hunting gun, that recoil beating is going to get real old real quick.

I'm not familiar with the Pacific UH's, I use a different brand, but they appear to be the same as most other UH's, very simple & reliable system. If you're looking to swap barrels, the UH is the way to go, simple enough to swap the barrels and they anchor securely every time.

With the UH, you can use any barrel profile you want since they were transitional period guns - it's not all that uncommon to see them with oct-rnd & tapered oct.

Wood is not cheap no matter how you buy it because you need the same size blank for a UH butt as you do for a CF shotgun, plus the forend is much bigger than a standard CF shotgun so you need a bigger blank for that as well.

I can see your point about the specific use of the rifle. I guess since it would be a "long range" gun it should have sights or a scope to do the job. I never liked the looks of underhammer rifles because they just seem wierd or different but that's just me. Now I am considering one.

If you're looking for a dedicated long range rifle, especially in a bigger bore size, you'll want a longer barrel for both powder burn and sight radius advantages. If you want to stay somewhat historically correct, there were east European rifles similar to the Jaeger style done in 3/4 and half stock. They have had a robust stock especially the wrist and butt with 36+ long barrels.

Two things with an UH is that with a long heavy barrel, they quickly become muzzle heavy and there can be issues with the thin wrist breaking with heavy recoil. If you beef the stock up to counter the barrel weight, it just throws the balance and handling off even more.

If we're on the same wavelength here, I think you'd be better off going with a heavy built half stock and maybe a tapered octagon barrel.

More than 1/2 of the rifles shown in Kindig's "Kentucky Rifle in It's Golden Age" are either smoothbore or have straight rifling. Golden age rifles have octagon barrels. However, many of the original Pennsylvania gunsmiths also made fowlers that were strictly an American style. Barrels were octagon or 1/2 octagon to round and were long - up to 60 inches. A good reference is "FLINTLOCK FOWLERS the First Guns made in America" by Tom Grinslade.

Fortunately there are several fine makers today who can craft a period fowler.

The barrels I use on American fowlers are 42" long, have 13" of tapered octagon with wedding band transition to the round, the round is tapered with a mild swamp for balance and swing. Once you get over 44" of barrel, they get slow on the swing and are pretty much limited to fly-by shooting. Strait taper octagon to round or tapered full octagon are best for a long barrel rifle where you want to keep the center of balance (C-B) back far enough so it shifts the stability point off the support arm and back onto the shoulder. Once you get over 36" with a swamped octagon even in a "C" or "D" weight, they start shifting the C-B forward and moving the stability point forward with it. If you've got a good strong & steady support arm it doesn't really show, if your support arm isn't what it used to be, you'll really appreciate the strait taper barrel. I did some small youth/woman sized .50 fowlers & .45 rifles using strait taper octagon to round - keeping the weight shifted to the rear moves the stability point onto the butt and it makes them much better for offhand shooting.

The Eastern European Jaeger sounds really interesting. I'm leaning towards something like a Manton rifle or similar like the Mortimer rifle from Davide Pedersoli . Gunstocks Plus has a Manton style stock. I recall the shop which is in Oxford Ohio. I was in Oxford to see a girlfriend years ago and its beautiful hilly country there. http://gefrohbigbores.com/Gallery1/manton L@R makes a Manton and an Alex Henry lock but I'd rather have a Chambers lock. I have seen a Manton lock at the Rifle Shoppe site but it seems alot of work to put one together. These are auto- priming I think which is something to consider first. A double riflle with a sling would be real nice but that seems a bit out of my skill range.

If you like the Jaeger style, I'd go with the Chamber's Early Germanic lock and a wide buttplate usign the girth of the stock to control the balance of a 36-42" barrel. If it's going to be primarily used for hunting, I'd go with a single trigger.

I am still considering building a rifle with a very slow twist rate barrel for hunting with roundballs as was suggested here. Thinking about a 1:106 or 108 rate of rotation in a 36 inch to 40 inch .58 caliber tapered barrel. The main concern is the recoil it would have. Ive considered fowlers with a rifled barrrel, various muskets like the early version of the Baker rifle or 1803 musket, early Lancaster or Virginia or Clark rifles and even underhammer style on a shotgun stock. I am fond of fullstocks particularly Jaegers or transitional rifles like the Edward Marshall rifle. My question is this... Would an octagon to round tapered barrel or tapered unflared octagon barrel be too historically incorrect for a Jaeger or transitional rifle? I thought about a style similar to the Pedersoli Mortimer also. These are hallfstock but could be made to except an interchangeable shotgun barrel.

Twists slower than 1:72 are not needed to at least .69 caliber from reports I have read. My 66 has a 80" on it right now. At least not from the stand point of how much powder you can shoot. In a 36" barrel you will be limited to 100-130 grains of powder in all likely hood. Charges above this will likely produce little gain in velocity per grain of increase in the powder charge. A 40" will increase this somewhat but if you reach 1700 or so you have about all the velocity you need for the ball size. It will shoot flat to 130 yards for deer and elk purposes. Shots past this are not really a good idea at least not for me with the current state of my somewhat aged eyeballs. My 30" 66 Manton style flint starts to show signs of being maxed out for velocity at about 120 gr of FFG Swiss. 110 gr gives 1640 in a 96" twist and 140 gives only 1750. I will do further testing and likely back the hunting charge to 120 if it shoots OK. I have since rebarreled and while I tested it for accuracy I did not check velocity as of yet. Recoil gets abusive over 140 grains and can be bad off the bench at that level with a 10 pound rifle. My 38" barreled 54 makes almost 1900 with 90 gr of FFFG Swiss.
An "American rifle" will tolerate heavy loads in 58-62 caliber if its the proper design. Earlier flint guns with wide flat butts will do well here. There were short rifles made circa the revolution. Probably 32-36", the writers that mention them fail to specify. The Marshall rifle, or similar, is an excellent choice for a 58-62.
The early Hawken FS plains rifle design (but not the precarves) will do OK but most of the cast buttplates for sale are too small for heavy loads especially in a 58 if the rifle weighs under 10 pounds. Heavier recoiling calibers would require a slightly wider shop made buttplate for the Hawken style.
British rifles have good recoil characteristics. The rifle in Track of the Wolf's "Purdy" plans would make a good choice. With a few minor mods it would work as a flintlock as well. Little longer forend and perhaps 2 barrel keys. Basic stock design in the same. Uses British fowler buttplates.
1/2 octagonal barrels often tend to have strange stresses in the steel I prefer full octagonal or full round. For what you want I would use the Purdey plans (Purdy apprenticed under Manton) mentioned and make it a 28-32" 1 1/8" tapered to 1" in 54 to 62 cal. Recoil will be pretty reasonable. 62 is a good choice but recoil will increase with the heavier ball. 54 is really about the bottom of the list for elk sized animals IMO. One reason I built a 66 caliber. Other is I always wanted one after reading a 1860s book by James Forsythe.
George's book on English Guns and Rifles shows 1 or 2 FS 1790ish English rifles with full stocks. Buttstock in very much like the one pictured below or the TOW Purdy nice guns.
A swamped barrel with a flare at the muzzle will not need as high a front sight as a barrel with a straight taper so a swamp has its advantages, however, a straight taper barrel is fine for about any time period.

Dan
Still in the white.
http://i72.photobucket.com/albums/i199/DPhariss/ML%20Guns/P1020561.jpg

1/2 octagonal barrels often tend to have strange stresses in the steel

Maybe from certain mfg’s but there is no difference in the machining processes used to make octagon to round than a full octagon or a full round. My octagon to round barrels have all been tack drivers.