I'm using them in my 1851 colts. They are tapered, and fit in the cylinders good. All it takes is a little pressure on the ram rod to seat them and well-ah! The paper cartridge is nitrated, and burns completely leaving no reisdue. No need to use a nipple pick either.
I have figured a faster way to make the cartridge, and may try to post it on Youtube with help from my son.
I have figured a faster way to make the cartridge, and may try to post it on Youtube with help from my son.