the one thing we forget to factor in when compressing the base of boolits is that the unlead spots [lube grooves] are a liquid under pressure and heat.
this is why I fill the area above the gas check with lube.
even Elmer believed that the base of the boolit being compressed by gas pressure would hydraulic the lube outwards onto the barrel face.
we have to remember Elmer wasn't an Engineer he was just good at observing things and thinking his way through what he was seeing.
pretty good writer too.
but he was basing his predictions and changes on observation.
we can all do the same exact thing.