I have a couple Lee REAL moulds (320 grain 50 and 380 cal 54). The 50 and the 54 slug out to .001" and .0014" oversize. I can get 2" 5 shot groups at 50 yards with *very* carefully selecting the bullets I cast.

I tried paper patching with tracing paper that measured between .0021" and .0024" and the results were decent and not so good. Due to the shape of the bullets I am not wrapping with a trapezoidal pattern. They won't stay wrapped as I am not sizing them after they are wrapped.

I wrap a single time around it with the paper split running down the axis of the bullet.

I guess my questions are: what are people's experiences with paper patching muzzleloaders? It seems to be a BP cartridge thing, not a muzzleloader thing.

I tried "beagling" the dies with foil to get them cast a little wider but that damn foil comes off after 5 or so casts. The foil gave me an extra .001" diameter. Paper patching if it worked consistently seems a better solution that slightly out of round conicals.

Lapping the dies was another option but it seems pretty easy to screw up your molds. The mold will wear more around the mold split than it will anywhere else when you are lapping with the two halves together (from what I read).

I thought I would try rolling papers as they are thinner. I have a couple packets in the garage as I use them as feelers for end mill offsets on the mill. They run just over .001" in thickness and are surprisingly tough. Maybe they are not paper made from trees? If I could find cotton based tracing paper I would try that.

I would doubt that PP a REAL bullet will result in any improvement.
As for ML bullets, paper patched, they were used in a false muzzle, which pre engraves the rifling onto the bullet.
Alternatively, the bullets are bore diameter and rely on the BP bump to obturate them and seal the bore. Most target breech loaders were loaded with bore diameter bullets. There were also breech loaders, that used muzzle loaded bullets too.
So, I think, a REAL bullet paper patched, is an idea I would not even try. It is mixing loading principles.

I am not super unhappy with the 2" 50 yard groups. I think they could be better, but my biggest concern is how loose the REAL bullets are in the bore. At the range it isn't an issue, but if I am bumping around while hunting I don't want those bullets coming off the wad. That could be bad and why I am looking at obtaining a better bore fit.

That reminds me I should have noted that I only get the 2" groups using a lubed wad between the powder and the REAL bullets. The wads are Ox-Yoke Wonder Wads and the lube is a bog standard mix of 50% Beeswax, 40% Crisco, and 10% Canola since I am going into details.

Having paper patched bullets would secure the bullets in the bore as well as hopefully improving accuracy. I saw mixed results with the accuracy, but I am pretty sure from the additional force needed to load the bullet, they bullet would not come off the powder/wad combination.

The next alternative would be a couple of Lyman Plains molds, and if that doesn't work then a custom die. The Lee REALS aren't terrible at the range, but they do require some care while casting. I get a ton of rejects to maintain a +/- 0.5 grain variation in bullet weight. The lead has to be ~800F and the mold kept very hot to fill them out properly. I wonder if 1% tin would help fill the molds out better but I haven't tried that.

One more thing the REAL absolutely sucked with a FFF loads. Only "slower" FF sized powder seemed to work. Perhaps the steeper pressure curve blows out the thin rifling engagement?

I have used a lot of REAL bullets in various calibers since they came out. They should NOT be loose; the first band should be bore diameter; the second one should lightly engrave, and the top band should be groove diameter; this will hold the bullet in place no matter what. Some designs and weights have 4 grooves.
Paper patching REAL bullets will be a waste of time for me. I can get the same two inch groups anyway.
Plus or minus .5 grains is a waste of time; I guarantee you all get the same accuracy at much higher variation.
Yes, 3FG is not ideal for .50 cal rifles and larger. Too fast.
I have also used Lyman Great Plains bullets; they won't move off the powder either.
If your REAL bullets are loose in the bore, your bore is too big for the bullets.
I don't use wads wither.
Been shooting MLs since 1967.
Another thing I have tried; wrap the bullets in white Teflon tape; easier than paper and far tougher. That will keep your bullets from fallout out.

Thank you for your responses. You have a good deal more experience with muzzleloading than I do. It's good to hear I can lighten up on some of the weight deviation without affecting accuracy.

How did you like the Lyman Great Plains bullets? They are another tapered design from what I read, and easy to load.

I think those conicals are short enough for my medium twist barrels. I have 1:48 twist barrels in both of my rifles. If I had to do it over I would buy a 1:28 twist for a dedicated conical rifle and a 1:66 slow twist for a dedicated PRB rifle.

I would love to be able to use the Lee 500 S&W die in my 50 cal, but I am pretty sure my twist will not stabilize that bullet.

I will load a fully filled out, exact weight REAL in each of the rifles and shake them around. I'll check to see if the bullet comes off the powder. I do get engraving on the first band, and a little on the second. I get no marks on the third or fourth bands. The third is maybe 0.001" under land diameter and the fourth is .004" or .005" smaller. They just seat with so little force after they get past the muzzle that it gives me concerns.

Unless you have a double rifle, those bullets are not going to fall out.
I have never weighed any cast bullets, now many thousands of them later, for MLs. Definitely on need for .5 grain variance; that is tighter than a jacketed match bullet. Almost.
It does sound like your bore and bullets are not an ideal fit.
I like the Great Plains bullets but I am not sure they make them any more.
I actually shoot CVA Power Belts in a Kodiak .54 and Sabots in a .58 Kodiak; those have 48 twists, and shoot fine for hog hunting, meaning into 2 inches at 50 yards for both barrels. The 58 is a bit larger, but each barrel is perfect. So a one in 48 will do more than you think.

I recast the REAL bullets using a 1:40 tin/lead alloy I mixed. I am getting a better fit in the bore. The third band is now right at bore diameter and the top two show better engraving. I assume that the tin is lowering the surface tension of the allow is allowing better fill in the mold as that is one of the effects of tin in the alloy from what I read. I'll take some out today and see how they shoot.

Adding tin does make bullets slightly larger. Usually up to one thousandth. They will shoot fine; and no need to weigh them; they will still shoot the same.

I didn't find much of a difference in group size. The bullets did have a better fit in the barrels. I have tried everything I can think of and these REAL bullets just don't group like Maxi-Balls. I brought some Maxis with me today just to compare. I shot a 1" c/c 5 shot group at 50 yards with no work up at all. I'm giving up on the REALS. I will buy a set of Lyman Plains conicals and see how those work.

Because they don't fit your barrel. They are made for hunters, and a two inch group will hit any deer we have around here. I have found that Maxi balls are not as accurate as others, but were fine for 100 yard deer.

quote:

CVA Power Belts

I forgot to say I need traditional, full diameter projectiles or PRB for hunting here in Idaho. They have to be lead or lead alloy and within 0.01" of muzzle diameter. I am not sure if I can use Powerbelts here for hunting or I would try the lead version of them for the 50 caliber.

Also instead of going to a Lyman Plains I see that Accurate Molds have a mold similar to it. Perhaps I can get one sized for slightly oversize bore. If the issue with the accuracy is the bore size moving to another standard size mold like the Plains isn't going to help.

Thank you for your input. We have very few muzzleloaders at my range. Almost every bench has an AR-15 or a 10-22 these days and sometimes both.

How about an AR-15 Muzzle loader? I build them too!
Power belts are bore diameter, well within your .01
dimensional tolerance requirement.
If you get a mold that is groove diameter, that will be impossible to load.