Good point, SmyleeG - a 'cone' that is 1 1/2" deep, is more like a funnel.
The problem loading Leatherbelly's rifle with the long cone, was the long bearing gradual surface, which increased the friction and pressure needed to seat the ball.
That is the only way I can understand why it took a LOT more pressure to seat the patched ball, than into the short crown we make. I read a letter written by Corbin
(bullet swaging/forming/re-sizing die company), who showed a picture of a die with the same from of 'shoulder' that we put on our muzzles, this rounded shoulder is
the correct angles and finish for moving "metal". I tried this/these angles on a muzzleloading rifle's crown back in the 70's when I was interested in what Corbin's was
doing and found it works.
Had a lad at the Barnet rifle range (Burnaby B.C.) complain to me he couldn't load the combinations I was using in my identical rifle. .50 TC Hawken(s). The combination was
a .495" pure lead ball (telephone cable junction sheathing) and 10 ounce denim patch. I looked at his crown, and it was still the standard sharp cornered machined crown.
I use a pocket knife and cut the corners a bit, then a piece of emery from my possible's bag to smooth the crown. I then took one of his cast balls, piece of .022" denim and
loaded his rifle, just as easily as I loaded mine, using a starter and his 3/8" factory rod.
Here is one made by Dave Crysali, with a tool of his making.
Another, by Brian Barker.
A couple of my own.