Just got in the Verlinden M109 equipment kit...
It has what looks like a propellant charge (with Live Resin PASGT helmet for scale)...
those powder canisters look like green bag canisters. Seems like there was (are?) two full sets of charges in each can. White bag is shorter and about two or three inches bigger in diameter.
Take no offense, but the powder bags look like nothing I ever used (plastic). The bags are actually packed pretty tight, and the red end is very blunt with the red flash pad being proud by about a quarter inch (same for white bag). When we cut charges, we'd hold onto the very top ribbons and simply push out what we didn't want. Then while still holding onto the ribbons we would simply spin it till it was tight. Then tuck the remaining ribbons into the side. Quicker and once in the breech nobody cares is you tie it or glue it. After the mission, the left overs are dumped away from the gun
Honestly; we never had a lot of left over powder unless you could almost see where you were shooting out in front of you. Yet on some LZ's we'd fill a pick up truck daily (six guns). Just not the norm. Charge sevens were the norm from five klicks out to max range.
Does (or did) the M198 use aiming stakes? I'd think so, but I'm also real old.