The first inline i actually saw someone shooting at the range was being fed powerbelts. The guy told me it was his favorite deer dropper. It was a CVA (Optima, i think)
He was making egg sized groups with it at 100, but his rate of fire was very slow and methodical.
He'd shoot, remove the breech plug, wipe and grease it, douche the barrel with a wet mop, run a bronze wire brush tip to remove the plastic several times, a cleaning patch, run a bore butter patch down the bore, reinstall the plug and reload. He said he liked to make every shot on a clean, cold bore. I think it was two 777 pellets behind 300 grain PBs.
Apparently the bronze bore brush dragged the plastic out in his routine.