FF&S Gun design nit

Two points:

A 4 guage shotgun is over 20mm in bore diameter yet 'technically' can not
be designed.  (A friend made the valid point that it isn't really a small
arm as much as a cannon though)

The rules say that you cannot have necked cartriges in a grip magazine.
The Soviet Tokarev used 7.62*25mm NECKED cartriges.
My junior gunsmith friends say that necked cartriges actually feed better in
Autoloaders.

just a couple of nits in a pretty good product.