Should conical shave lead at seating ?

[M. De Land]

I've not much experience at conical shooting in percussion revolvers and in our recent discussion on stepped chambers I began to rethink this question I've had for some time (about the need for conicals to shave a lead ring) as to the differences between ball shooting and conical use.
Balls will self center under any ram face profile but this is not necessarily the case with conicals and especially conicals with square bases. Shaving a perfect lead ring to insure base seal is not a guarantee on bullets and this is where the tapered chamber and heeled bullet profile would demonstrate an advantage in my opinion. My educated guess is that the gradual taper would probably promote better alignment accuracy and gas seal than a step that I previous thought an advantage. The steps I have cut have a 45 degree transition taper but the Uberti taper is much more gradual and I think to be preferred.
The chamber mouths still need to be opened to groove diameter but the chamber cut of more gradual taper like Uberti apparently does. A taper reamer would need to be fabricated and I haven't made one in a few years and need another project like a tax audit but I'm approaching the curiosity level that may pull the trigger on this deal if I can ever get caught up on the others.
The easier approach will be to fully ring out the Uberti chamber taper and see how it pans out before embarking on a new reamer make.

 

[nkbj]

What I've seen over the years was that tapered chambers had good points and bad, trade offs like most everything in life.
In the past the machining of chambers suffered from a lack of consistency in the completion of operations (bad quality assurance). When the depth of tapered reaming was not precisely controlled the diameter at any given depth varied from chamber to chamber. Another down side to tapered chambers is that light loads will squeeze the balls down to smaller diameter if you weren't using cornmeal or cream of wheat. But, that said, the up side is that taper does give a better seal. And if the chambers are consistent and your loading ram pressure is consistent then you have double good.

Something to note in passing, some people find that generously beveling the chamber mouths so as to avoid shearing any lead works well for them and that's a really generous taper.

 

[M. De Land]

What I've seen over the years was that tapered chambers had good points and bad, trade offs like most everything in life.
In the past the machining of chambers suffered from a lack of consistency in the completion of operations (bad quality assurance). When the depth of tapered reaming was not precisely controlled the diameter at any given depth varied from chamber to chamber. Another down side to tapered chambers is that light loads will squeeze the balls down to smaller diameter if you weren't using cornmeal or cream of wheat. But, that said, the up side is that taper does give a better seal. And if the chambers are consistent and your loading ram pressure is consistent then you have double good.

Something to note in passing, some people find that generously beveling the chamber mouths so as to avoid shearing any lead works well for them and that's a really generous taper.

I have noted in cartridge guns that to much chamber mouth chamfer encouraged and increased lateral gas escapement and increased gas cutting of the top strap although not an issue for open frame guns.
Lead spitting is from misaligned chamber to barrels and/or forcing cone profile and not gap width or chamfer.

 

[nkbj]

Misalignment...
Something I've noted is that one of the advantages of long bullets versus short bullets is that the front of the bullet can be used as a bore alignment tool. When the bullet comes out of the front of the cylinder and into the bore of the barrel, if its shape is conducive to the function then it can create alignment for the following groove diameter portion of the bullet.

 

[AlexB]

Using the standard .45 lee mold that doesn't shave in my Piettas they sometimes back out under recoil.
Shooting 30 or 35 grains t7 or pyrodex as a standard.
The kerrs from eras gone shave a good ring and don't back out.
.454 lee mold rounballs shave excellent rings and don't back out even with a 45 grain t7 charge.
Balls shoot tighter groups overall though.

 

[nkbj]

Round ball found to be the more accurate bullet is often the case. It's an easy profile to create satisfactory castings, it aligns itself during loading, the round hind end prevents the sideways thrust created when a misaligned flat bottomed bullet exits the muzzle; all good characteristics. Overall it lets you avoid load development to get good enough, same as buying a box of cartridges at the store.

 

[CVA Enthusiast]

YES if forgive me, I went back to round ball several years ago but if I recall correctly the conical is a little over sized also so there should be a little ring of lead indicating the "Seal"