How do you load it? With an accompanying truck full of projos and a team of gorilla men?
Reportedly, it’s a semi-auto loader like our Paladins’ guns. It’s not known if the thing has any on-mount ammo storage but if it does it’s not much. Our Paladins carry some ammo internally, but even they have to be restocked by a supply vehicle and crew. In this case, the M992 resupply vehicle and a crew (the stupid automated conveyor thing didn’t work and was slower than humans).
The M109A6 can fire 36 times before it runs dry and has to reload, the M109A7 can fire 39 times. I’d guess the PCL-181 might *maybe* have 5 or 10 rounds on it. Then again, it’s not really filling the same role as our Paladins, being truck borne and not tracked or armored.