shred that is a very nice looking mortar ! If you ever put 100 grs of powder in it ...you will just think it a noise maker . Not unsafe if it built correctly but you will never know where that ball went !
Does it have a chamber ? If it does then that should be your guide . 25 grains of 2f will send a pool ball @ 75 yards in my 2.1/4" South Bend cohorn mortar .
There is a pool ball down range where we shoot ...it is less than 100 yards away from where we shot the mortar . I can not find the darn thing !
I've been looking three times now when we go to the Pawnee National Grasslands .
You could proly get away with 4F in very small quantities ... maybe 5-10 grains to start ,but if you can get 2F OR 3F you are in bidness ! But still start with 15- to 20 grains . It is amazing how little powder it takes to send a mortar shot along way it is because of the chamber .
The fun of a mortar is watching the ball soar and then plunge to earth with a terrifying thump ,THEN you go pick up your balls and do it over agian
yea it's very cool .
Good Luck ...and Welcome ! shred / Nice looking piece