Buckshot in a Musket works very well.
Buckshot in a Musket works very well. With only three lands and grooves in a very shallow cut, and very sparse turn, it doesnt hurt anything.
I have an old .58 cal Zouave that I have been shooting for 25 years or more. Several sizes of buckshot have been shot out of it and it patterns reasonably well for hunting or whatever else.
Single Fg or FFg propels it just fine. I do like the Fg in a musket, personally. I shoot it anywhere from 50, 70 to 90 grains depending on what I am doing. It can be a pretty stount charge for buckshot, though I suspect hotter charges are probably wasted on buckshot. Use some wadded up paper or rag or a couple 2 or 3 of patches tamped down over the powder. Drop your shot in. You can buffer it with cornmeal or cream of wheat if you like, but you dont have to. You need some over-shot wadding to keep your shot in the barrell so it wont go rolling out. Many things work for that. Paper wadding MIGHT set the woods on fire, so watch what you do. 1 ounce of shot is all that you need. Put your top-hat cap on the nipple, point her South and pull the trigger. BOOM.....and you have a serious charge of buckshot flying down range.
Number 3 buck throws an excellent pattern out of the Zouave. 00 doesnt pattern really - it sort of does what it wants to do in the general direction of the target. 3's work out pretty good. I suspect that 00 likes a bigger bore than the .58 cal.
I had some 4's I tried a few times - I didnt have lots of 4 buck shot on hand, so I didnt shoot alot of the 4s - and it behaved like the 3's pretty much. I took rabbits with the 3's and they cleaned up nice. I am sure that it would take a deer at 50 yards with no problem, if you are of a mind to buck-shot hunt for deer. I would rather use a round ball and a patch on a deer. Some people like buckshot hunting, though.
The rabbits I shot cleaned up easy because almost no shot stayed in the rabbit, and what did was easy to find and remove from the hide and meat, unlike using tiny birdshot.
I had one sack of lead shot in BB size that was given to me and so I shot quite a bit of it out of the old Zouave over the years. It worked really well and threw some pretty decent patterns. I took squirrel with it using a 50 grain charge, and it worked out just fine.
None of the rifling was disturbed in the musket. It stiull shoots balls and minies just fine. I would not do the buckshot trick in my Thompsonb-Hawken, simply because the rifling is too agressive. But in the Musket, the rifling is very shallow and very slow. You can shoot buckshot out of it because of that. They even had some loads called buck-and-ball in the old days that were paper cartridges used in these guns back in the 1800s. They contained one ball and a few pieces of buckshot in one charge. It was actually a military loading.