Daryl,
helpimg as usal !
Thanks for the info, I could never underestand the reason until now. Thanks.
I would like to try regulation a little before investing in a special mold, so Im reloading some cases with two bullets, the "paradox like" I mention on another post and some 20ga solid slugs recised to .600".
The charge will be 50gn of FFFg and a active wad of 25gn of powder and the same volume of corn meal. Coyote from Britishmilitaryforum give me this charge.
I had bad luck with wads because some of them stick with the bullet part of the way to the target.

I had to do the same to my Kodiak as have some patch cutting.

Thanks
Martin