These are the "inserts" for my Stience15, you could call them shells but since they bring their own barrel it wouldnt be that accurate.

except the solid 177. ones all work with the same iso-screwed bottom.
Yes there are more calibers but i dont load up stuff that i didnt test.
So this is the first part

Yes they share their dimensions with 12/68 shells, so they should work fine in a (breakaction) 12g-Shotgun for training or plinking purpose.
just don't try this backwards and throw in a shotgunshell into the launcher this would be guarantied trip to the hospital or mortician..

Do not add any powder at all.
A 209-primer is the only energy those need.

ps: forgot the printersettings

Printer: Anycubic S1 Combo
Filament: ESun Pla+ Firetruckred and Sunlu Pla+ Black
Layerheight: 0.2
Scarfjoint: yes, Hole and Contour
precise wall: yes
precise z-height: yes
ironing: no
walls printing order: outer/inner
wall loops: 8
top/botttom: 5
infill: shouldnt matter, modell is all walls with 8 loops but i allways use concentric with 99%
Speed: i used the high quality preset vom anycubic next slicer and didnt change it for the inserts a single Bottom prints in about 17 mins
Sequence: print them by object not by layer

LBRY Tags: printing; 3d2a