Here is picture of the Mauser GEHA shotgun I
setup with an Savage 210 rifled barrel. Used a Savage
plastic stock also. It is setup with the original 3"
chamber. I have many guys who want ideas and slug/load
combination's tested in regular rifled slug barrels, so
this is the one. Most testing will be 3" plastic cases.
Barrel 24" long, .93" regular slug size muzzle diameter.
The GEHA was originally converted from 98 Mausers in
Germany in the 20s, to 12ga by reaming outl the front lug seats
and using the rear safety lug. I added a second rear
bearing lug and it handles 15,000 psi loads ok.
The cases come out with the weight of the bolt.
That will be max pressure used in it, with that slug gun
barrel thickness. Example load is 115gr of RE17 in 3"
plastic case, with 520 gr Lyman cast slug at 1850 plus fps.
This load expands the plastic case base cups about .005",
in comparison, a REM factory Buckhammer and other super
mag turkey and goose loads expands .010".
And we have over 300 fps more velocity.Ed

[Linked Image]

Ed Hubel