Hello All,
I would first like to say hello to all from Alaska. All the muzzleloader shooting up here is 100 yards and less. I have always known that muzzleloaders could be accurate at much greater distances. But all of the people up here are what I call traditionalists. But I have always been known for doing things a little bit different. I have a few questions for you fellas. I want to build a muzzleloader rifle. A muzzleloader that I can hunt Moose with. The law requires me to use a 45 cal minimum, which is the caliber I want to use. But I also want the muzzleloader to be capable of shooting what would be midrange for you guys (500 yards or meters roughly). I figured I would start out at a modest range.  
  I have been looking at the �English Rigby Sporting Rifle� kit from Pecatonica River Long Rifle Company. I like the fast twist 1:18� barrel. But the drawback is the stock looks more modern in shape than I like and there is no ramrod. I would like to put that barrel on a Hawken full stock (I like the double set triggers). But I don�t know if that would work. It may punish me for pulling g the trigger. The Rigby�s butt is 2�x 5 3/8� and the Hawkens butt is 1 7/16�x 4 3/4�.  So I don�t know if it will even work.  
As you can probably tell there are quite a few things I don�t know about long range muzzleloader shooting. Like how much powder do you use for a shot about 500 meters? I read on a website that 60 grains of fffg and a .451 cal conical is a recommended load for long range shooting for a Gibbs. I am guessing the conical would weigh in the range of 400-500 grains. Could this be true, that little amount of powder propelling that heavy a conical bullet for that range? I talked to a gunsmith in PA that was saying 150 grains of powder and a 560 grain conical for 1000 yards or meters I am not sure which.
Everyone up here says to use a 54 cal round ball or a 62 cal round ball Muzzleloader at less than 75 yards. I know muzzleloaders can be more accurate than what they are telling me. I have lived in Alaska since 1962. And have hunter moose with a .270 centerfire. So I know it�s not the caliber of bullet that gets the game it�s the placement of the shot.
Well that�s enough questions for my first post. Thank you for taking the time to help a newbie.
Alaskan Hunter

I like the thought of being different. I agree that a curved buttplate is not what someone needs for a rifle that has significant recoil. The classic English stocks are not exactly user friendly as far as recoil is concerned also. One thing to consider is that shooting at extreme ranges is more or less 'lobbing" a projectile so there will be alot of rise and drop involved. (I think) a round ball rifle would shoot flatter than the type of rifle this board is concerned with out to "normal" hunting range as you mentioned. The larger roundball calibers do have better ballistics. You can have a straight sporting style stock without the pistol grip. Take a look at White Muzzleloading. He has a English sporting rifle with a straight stock without the grip. These do not use paper patched bullets but "slip-fit" bullets instead. I would prefer a papwer patched bullet myself for various reasons. A double percussion rifle would be nice to have. You could even make one barrel for long range. Traditional is a  term that is relative. Underhammer rifles look different and unusual but they are 'traditional". They were all the rage at one point in New England. I suggest looking at beartooth bullets forum. There are a few builders that have the type of rifle you mentioned for hunting there. Just trying to help. Good luck with your Alaskan hunting rifle.

One thing to consider besides the shape of the butt plate is the dop on the stock. The straight English stocks are suited to long range shooting where elevation for sights are high compared with PRB at short range. With the drop in the stock I have seen on many traditional American rifles you may find that when on aim you only have the upper part of the butt plate making contact with your shoulder and have little contact with the cheek piece.
 
Charges of fffg powder are used by some for .451 match rifles and light charges may be suitable for short range work. Most shooters though use coarser powder (commonly Swiss #3 / 2f or Swiss #4 / 1.5F) and charges of 80-100 grains. Nipple erosion is a factor and these will typically be lined with platinum.  
 
David

Alaska Hunter:
 
Currently building the Pectonica Rigby "kit". �I have built a Hawken from Track of the Wolf, a pistol from no where (my own parts from an old gun and some purchased) and now the Rigby. �Although the Rigby does not have that nose cap / rib / ram rod intersection (no ram rod) the barrel / tang is very tricky, with a bolt running down from the tang to the trigger boss and one running up to the underside of the tangs hooked breech. �The pistol grip is traditioal on this gun and it makes an interesting project by itself.
 
I currently have a mold for a 535 grain .450 cal. bullet. �The thing is huge! �My 60 cal Hawken has a very large ball that only weighs in at 317 grain.
 
If you go for the long range sights - get ready for sticker shock. �
 
If you are interested in photos of the build (as paulbehe says, there is no instuction kit) there is a link in the "English Match Rifle - Build" of this forum.
 
Mike F