"On the other hand . . . with a blown end from the shell also going down the barrel, we have now increased ejecta WEIGHT vs the same shell without the end blown off. So that might be a possible explanation for a noted increase in recoil. Although not a lot of additional ejecta weight . . . who knows?"



OK guys no sense guessing about the theoretical. To make life easy I have included a link to an automated recoil calculator. Plug in you numbers and find out for yourself.

http://www.10xshooters.com/calculators/Shotgun_Recoil_Calculator.htm

I think any increase in recoil that could possibly be attributed to a little bit of dislodged plastic will be negligible at best.