20ga. shotgun to 60cal. musket

Hello All: Not sure if this should be here or at casting for shotguns. I own a Rossi 20ga. 3" fixed choke modified smooth bore. This shotgun has a hammer with a transfer safety plus a toggle safety on the side. This, with the low price of just over $100 makes this a good choice for a 60 caliber musket in my thoughts. I've purchased a 209 primer adapter to convert the single shot gun to a muzzle loader from Short Lane. I'd like to shoot a .600 round ball and on occasion some buck shot with black powder. My concern is with the fixed modified choke, what would be a good choice for wadding? I could just load shotshells but I don't see this as an advantage using black powder as it isn't a weak action gun. I have on hand some 20ga. muzzle loading fiber wads that are lubed but I'm not sure they could be tamped in enough to provide a seal after passing through the modified choke. I've seen a video of a survival sort where sheeps wool was used for wadding. Do any of you have thoughts on a better material for wadding in this application? Thanks Gp

I had a similar idea my only problem with the idea was that the chamber area is larger ID than the bore, so patching a ball is theoretically a no-go (I haven't had a chance to try it yet). A chewed ball would probably be a better choice, and maybe stuff enough wadding in there to take up most of the chamber area?. I have used all kinds of "crammable" (is that a word?) stuff for wadding- wool, wasp nest, newspaper, packing paper etc. the latter two tend to hold an ember more so beware of shooting is dry combustible environments.

Tow (flax) fiber makes an excelllent, "crammable" wad too. You'll want to search for Jas. Townshend as one source. Susan Wallace is another.

make a breech plug that takes up the chamber area.

I may be making this harder than it needs to be. After giving it more thought, I believe I'll just work on round ball loads using the 20ga.shell casing, either black or smokeless powder.

Might be best to remove the choke by reaming it out. The bore on a 20 gauge should be .620" and with no choke you could use a .610 ball. Making a chamber insert would be a good idea but would need to be about 3&1/4" long and tapered to fit the forcing cone. The inside of the insert could be bored about 3/8" or what ever size to allow for about 60 grains of powder. Might also install an O ring around the insert to keep it from leaking. A good way to figure out the size for the insert would be to pore a chamber cast. With this setup you should be able to load with no air space between powder and ball. Many years ago I shot round ball out of a 12 gauge and was able to hit pop cans at 50 yards.

Thanks for the replies Guys: Looks like the much cheaper way would be to just pick up a beater 12ga. as Short Lane makes a chamber insert for black powder in the 12. I don't think they recommend it for use with RB but it's along the same line of thought John mentioned. My sign on motto used to be "If you don't think too good, don't think too much" lol Gp

This is muzzleloading? I would advise against trying to load a ball down the muzzle of something with that degree of choke.[smilie=b: If what you're loading is a fowling piece which is 20 bore and cylinder to the muzzle then there's plenty you can do to make it fire a round ball very well but it sounds like you're trying to turn a breech loader into a muzzle loader...true?
Just re-read your initial post. I advise against this.

I'll admit I know very little about this subject-- but the engineer in me wonders if the pressure it takes to drive a round ball down the barrel might not be lots higher than the pressure it takes to launch shot. Will the breech take the pressure??

I see a couple of problems - 1st is the choke but I would think that you could ream/polish it out? Second though, is the chamber. The only way to make it a "muzzleloader" is to install a fixed breech plug - which,if you have the right tools could be made and installed - as you want a consistent ID the complete length of the barrel. Being a muzzle loader should not affect the pressure it takes to put a shot or ball down the barrel any more than if you used a black powder shell in it.

I'm sure that it would be a "doable" project but it seems like a lot of work to getting to a 20 gauge muzzleloader over just building one. A 20 gauge is a good size as far as either shot or ball (ball for large game). I have a flint Fusil-de-Chasse in 20 gauge - have taken birds as well as game with shot - circle fly wads work great. A .600 or 610 RB with the correct patch will work wonders - but again, my barrel is a straight bore smoothbore.

You really don't gain anything if you use, say a brass shell to fill the chamber as if the action breaks and he shell is removed, you really don't have a "muzzle loader". Before you go to all that work - you might just want to try loading some
BP shotshells and using those - it will still be lots of fun. You can either buy brass shells from such places as MidwayUSA or others or use used hulls. If you aren't able to put a crimp on them, then cut the hull to fit the length of the chamber, load as a normal BP shell and after putting the over the shot card, just seal the circumference of the card with waterfalls, a dab hot glue or a suitable glue such as a white glue. if yu decide to load a RB slug" load, then measure your muzzle and get the right size RBso you aren't trying to put a large ball through a little hole.

Just some thoughts - it will be interesting to hear what you come up with as there is more than one way to skin a cat! Good luck and let us know!

Well Guys, thanks for your thoughts. I'm somewhat of a computer Tard so bare with me here and I'll show you what got me started with this thought. https:www.gunadapters.com/ 209 muzzle loading series. 20gauge to 209 muzzle loading adapter. Then choose options. 209 primer adapter by David Canterbury. http://www.thepathfinderstore. This may get you there without the above but I wanted to show you where to get these adapters from Short Lane. Check it out and your comments will be welcome. Gp

To the above, I would like to add this. No matter what it is that I would expect to exit the barrel, I would first make sure it could be pushed through the barrel with little pressure. this would be any round ball or slug shot over or in a wad. Gp

An interesting bit here
https://www.google.com/patents/US4437249
thought out a bit better than the shortlane unit IMO

I would use a 20 Bore Brass Case minus the primer.An example of alternative ignition where the Snider Rifle could be converted by removing the Long Firing Pin and replacing it with a Long thin Tube that doubles as a Nipple for Top Hat Caps.I believe it was intended for when ready made Rounds had run out the Rifle was then used as a Muzzleloader.I personaly would remove any choke for safety sake.I have one of those conversion tubes somewhere amongst my stuff if I can ever find it.
The 20 Bore Smooth Bore Muzzle Loader was apparently much favoured by those around the Hudson Bay Co for its versatility as a Shot and Ball Gun.

Thank you for that link Buckshot Bill. That chamber insert in the working drawing and a cylinder bore shotgun seem most likely to be a success. I've received some great thoughts from folks I admire here on the forum. Having one made up as a one off by a machinist would most likely be cost prohibitive. I'm dropping the idea of shooting round ball with the Short Lane adapter. They , as a company don't recommend it. If I continue to chase the idea of shooting solids out of a 20ga. modified choke it will be with the use of 20ga. three inch hulls. It doesn't seem there is enough room in the 2 3/4" for an adequate charge of BP. Again, thanks for sharing your thoughts and for giving some insight into how this could be made to work and not just blowing it off as a dumb *** idea. Gp

Just for the "can it be done" aspect, I've cut a shotshell at the brass / plastic junction and loaded a primer into the modified "hull". Loaded the brass into the chamber of the shotgun, INSURED A GOOD SAFETY WAS APPLIED, (in my case the hammer wasn't cocked on the single shoot shotgun) and loaded from the muzzle like any other ML shotgun. Worked great. YMMV

Good morning
Years back decided we needed a "up close double bear gun" in 12 guage. All the info is some where achieved here at CB ...
But with RB in our double Fox B barrels started reaming out the chokes at .002 increments. Found a .007 - .005 constriction was best for both barrels with RB using either smokeless or BP. Went down to .003 constriction and started to see flyers.
The barrels did not print on the same spot but both gave the best groups at 50 yards and farther. This was with a .685 RB (WW) in a plastic cup that gave good tight fit passing through the constrictions.
Mike in Peru

725: Yes, that is pretty much the same idea as the Short Lane chamber insert. After a few missteps with some ball and slug loadings I cut the cases at that point and at that point thought it would be better if the brass hadn't been resized in the Mec press and just reprimed for a tighter fit. Mike: thanks for chiming in. I'm envious of your weather right now. We got our white Christmas here in Idaho. Should be cherry time coming up down there. Thank you both for your comments. Gp