Ask a gunsmith to show you.
The maker of your Derringer is no longer in business. Sorry-
Not in the public domain
50 USD
All these 35 75 dollor bs they must me worth 300.00 that's what I just got for one unfired box and history not 35 75 they 300.00 now think virus not 20 yrs ago ha
5-10
35-80
Try e-gunparts.com
35-80
Davis Industries of Chino CA did, however, they closed in 1998.
20-80 USD depending on specifics
Whatever is available ought to be OK. (40grains.....)
Calvin Davis goes by Jazzy Cal.