Off and on over the years I've noted that with paper patched hollow based boolits the patch remnants in front of the muzzle sometimes show that the patch failed right at the lip of the skirt, apparently due to that being the point which the squeeze on the paper was greatest. Hollow based patched slugs in the .69 rifled musket was where it initially grabbed my attention, the patch fragments being rather large.
Have any you fellas noticed failure at the edge of the skirt? Did you come up with a lube to reduce the friction?
I've thought about using Paul Matthews' formula with petroleum jelly and beeswax or some other concoction, just dipping the base of the patched boolit in about a 1/8" deep hot pool of the lube.