The Pedersoli Pennsylvania rifle I've been helping a friend learn to shoot with has been shot mostly with .45 cal round balls. I made up some more after the factory 50 finished and rolled them over a file to give them a rough finish so they'd grip the patch better(a friend told be about this trick).
Afer weighing them, I was pleasantly surprised to see they were all within 1gn of each other. 130.5 grains give or take .5

Ran them through the cronograph and found that at 55gn of FFFg they were doing 2000fps, @ 65gn 2200fps and going to 70gn only showed a few fps improvement. Accuracy was best at 55gn so we stayed with that. I was somewhat surprised at the velocity this thing was giving but I suppose the 41 5/8" barrel might account for it.

I got to thinking...Muzzleloaders have always meant slow heavy bullets to me, but 130gn @ 2000fps is not that. So we have to step up the size of the bit of lead.

I tried a few other things; the twist is 1;48, supposed to shoot balls and the conicals, but most people have said that the balls shoot better.
I found that 240gn .45cal cast pistol bullets fit ok, without a patch and shot quite well at 50meters. I didn't get them through chrono, but if I could fine tune that bullet it would be better than a 130gn round ball for hunting in my opinion. Logically the next step will be to get the mold for the long conical bullets that Pedersoli offers, or preferably, use another mold, because the Pedersoli twin cavity round ball only casts well only from one cavity.

I tried using more candle soot, cleaning it, heating it, letting it cool more than the other but no matter what I did, it just would not cast a ball, only a squashed drop shaped things, while th eother casst perfect spheres.
I've head something vauge about this happening and if anyone can offer any advice I'd be grateful.

We aren't interested in sabot bullets since we want to remain traditional, so even the pistol bullets are a cheat I suppose.

I was unsure of what to expect from these round balls and I do think they will work fine for most hunting but a heavier bullet will be what you wish you had when a really big boar comes along. Who can reccomend a good one for .45 cal in a 1;48 twist? How heavy can it go? I recall the Pedersoli conicals are around 500gn, while I've seen molds for 250 and 300grainers on a link I found here somewhere.

Lee R.E.A.L.(Rifling Engraved At Loading) bullet molds are available in 200 gr or 250 gr. for under $20.00 US. I think the 200 is your best bet in a 1:48 barrel.
http://www.trackofthewolf.com/categories/partList.aspx?...ubID=126&styleID=980

T/C MaxiBalls or MaxiHunters should do the trick for you, too. They no longer list their moulds, but you could post on the CB forum or the Campfire to find one. Lyman makes a 245gr .45cal Maxi mould (and a 475gr .45 Whitworth mould if you want to get really heavy).

I'm skeptical that your 1:48 twist will stabilize a big conical, that being 400 grains and up-ish...though you might get a little mileage with a mini design(hollow base).
Check around with some of the BPCR guys or hook up to a site with a Greenhill calculator for info on that. http://www.eskimo.com/~jbm/

Thinking you'll need something like an 18" twist for a conventional 3 groove lead bullet design of 500 grains or so.

Having said that, there's nothing wrong with the RB load you're using other than it limits your range a bit. RBs kill.

A 45 caliber 1:48 twist will stabilize a bullet roughly 0.6 inches in length. Anything shorter, no problem. Anything longer, and accuracy will drop off quickly. Buffalo ball-ets (half roundball, half conical) have a 45 in 200 grains. That would stabilize well. Also, that barrel was never meant to shoot 300,400,or even 500gr bullets. There's a weak link in there and you'll find it real quickly if you try to turn your rifle into something it wasn't designed for. Hopefully, all your body parts will remain attached... YMMV. I hunt with a 44" barreled 45 flintlock, and the 130gr ball at 2000fps is nothing to sneeze at!! Put the ball where it belongs, and you'll be having pork chop for dinner.

Well, ManCannon has a good idea there, didn't think of the ballets.

There are likely some other aspects to this that would prove problematic but twist is your first hurdle.

Give the Great Plains 285gr. a try. I bet they will shoot good in your gun.

I tried the Pedersoli 250gn maxi bullet, which looks like the LEE REAL bullet with 60gn of FFFg but it didn't shoot as well as the round balls at 100m.

I was pleasently surprised to get a 1" 3 shot group, which then opened up with a 4th shot 6 inches.

I will try some differnt loads to see if the 250gn bullet won't shoot better.