Joe;
Fully agree with what you are saying here & especially in relation to the Parker's chamber. As to the L C Smith, I haven't really mesured any chambers to verify, but all the specs found in the "L C Smith Plans & Specifications" book show 12ga chambers as having a length of 2 3/4". I was under the impression that any Smith's having a chamber shorter than 2 3/4" would be a very old one indeed & would not as such have been designated for use with that length of shell. Do you have verification that Smith actually built guns with shorter chambers specifically for use with the longer shells as did Parker.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra