For what it is worth...........I have shot "hundreds" of REAL's cast from WW in .50 and .54 cal., without leading.
Back in the days of AOL Gun Talk, around 1995 / 1996, there was a lot of talk about this same subject. And a lot of good information changed hands.
Even before that, back in the mid to late 1980's we were discussing this on Prodigy!
Of course, this same subject has been in debate since the first wheel weight (WW) was melted into a bullet.
Back in the 1960's, I felt very strongly that if I could melt it, I could shoot it in a muzzleloader. That has not changed a lot.
It seems that you can cast some pretty hard flat base conicals, up to a BHN of about 12 / 14, and shoot them just fine in muzzleloaders, even using heavy powder charges, by doing two things.
First off....they must be tumble lubed with a Alox Lube. Soft, BP lubes, seem to "lead" every time.
Any of the "Shake & Bake" lubes seems to work fairly well. I used to use "Rooster", but I haven't found it in a while. Lee Alox seems to work just fine, and it is cheap.
Secondly...IMO,You should always use a wad under the FB conical when shooting WW.
I use plain ol' milk carton wads that I cut with a homemade
[url] punch....made[/url] from a piece of conduit of the right diameter.
The more knowledgeable refer to this milk carton wad as a "HDTP"......high density, something or other.....to me, it is a simple milk carton.
I'm sure the felt wads may have merit as a lot of folks praise them. It just seems that additional eight, or nine cents per shot, could add up pretty quick, if one does a lot of shooting.....another plus for cutting your own out of milk cartons, maybe.
I have pushed water dropped WW conicals past the 1900fps mark with both the .50 and the .54....and surprisingly enough, you will find a lower SD when using properly prepared WW, as opposed to pure lead. Albeit, I can not hold well enough to take advantage of lower SD's......
When casting, you must always remember that the harder the alloy, the smaller the diameter of the bullet...up to a point....when using the same mould. ie, pure lead may cast at .500, while Wheel Weights (WW), from that same mould will only be .497, or .498....A "Bump-up" die should be used in this case.
The big question to this is..."Why do we do all this"? Why are we even concerned?
It seems there are two schools of thought....one for the roundball and patch, and one for the conical. I will not comment on this as it is everyone's right to think and do as they please. I am not here to convert anyone to my way of thinking....both sides have merit.
Yet again, and it is very hard to explain, many of us just like to "tinker" with such stuff, and for those that feel the conical just may be superior to the roundball for penetration...those same folks also feel that the "harder" the alloy the "badder" the bullet.
I feel the culprit, in the leading of barrels, is nearly always the lube and diameter of the projectile.
Just my thoughts..........
Russ