1/4" into the forcing cone is 1/4" pushed into an area that is very close to bore diameter. It is also 1/4" of thin plastic, not 1/4" of thick virgin paper shell. Considering that American factorys routinely cut chambers 1/8" short on purpose, to seal the load, I think the 1/4" is a non issue as proven by Sherman Bell. I think we all know that this Greener and Burrard research is just so much bs compared to what we have available today. Let's face it, Greener participated in the "my gun penetrates more than yours does" bull. We all know that was just advertising as was just about all other ballistics conclusions of the day. Sherman Bell has nothing to sell.