Sorry about Gramma
I had to shoot ashes of a friend. He wanted to be shot out of a .12 gauge.
I was given the ashes to load a shell.Opened the crimp,dumped the shot/lead
then filled with ashes ,then rolled over the crimp.
The box w/ashes was around the size of a shoe box but a little flatter.
The box had a hidden latch sort of thing, I had to squeeze the sides and pull
a lip. It was something like that, hidden catch, then heavy plastic bag.
It was about 3-5lbs. he was over 220lbs.
When it was time to pop him off I almost shot into the wind but caught my self
Swung the gun and pointed down wind, let him fly. It was a stream of dust/powder 8' long 10-12 inches thick.
Do not listen about sabot , use something like flowers as a wad .Get some flower buds the size of the barrel, remember your not shooting over a chrono.
Do shoot down wind but stay away from other people. Do not try to shoot all the remains, only about a cup/hand full. With dignity scatter the rest of the remains at a meaningful location.
I have shot wood ash out of an air powered gun using a wad. 2-3 cup fulls, there was a little wind eddy that sent ash all over me. Try shooting some ash for practice , made damn sure the wind is going to pull the dust away and don't fu*k it up. It is a solemn moment to be remembered for a life time, your life!!