The British ammunition makers did a thorough study of this back when fold/pie crimp shells were introduced.This was well covered by Burrard long before either Thomas or Bell delved into it. As a result of their study all fold crimped nominally 2" shells were put up in a longer case which would have a similar loaded length to the 2" roll crimped case. Had the same length case been kept wad space would have of necessity been reduced plus it was feared the shorter loaded length of the fold crimp shells would be confused with a 2" sheel & fired in those still shorter chambered guns. This work started just prior to WWII & was finished shortly thereafter.
Unfortunately it seems neither Thomas nor Bell read all that Burrard reported & totally misquoted him on this subject. They cited older writings of his in which he emphatically denounced firing the longer shells in short chambers. This was of course from the days when the longer shell was still a roll crimped shell carrying a heavier load than the shorter chambered guns were designed for. At the time it was written it was "Sound" advice. As soon as the further work was done of putting the 2" load up in the longer shells with fold crimp he amended his earlier Warnings & in fact himself stated that the important factor was the load & not the length. He did further warn about using a too long roll crimped case in which the loaded shell length exceeded the chamber length & would be forced into the cone, still good advice.
It has always been a mystery to me why an old RedNeck HillBilly like myself could understand what Burrard reported on this, but neither Thomas nor Bell seemed to be able to, thus their stated Confusion & Misquotes.
