Re: PCP needs cleaning
PCP air rifles are properly cleaned by pulling an oiled patch through the bore 2 or 3 times immediately after use. PCP air rifles produce moisture, and the patch dries the bore and applies oil to prevent rust. Especially important if you have a Marauder, as the shroud holds in moisture.
All pellets should be properly oiled before using in the PCP rifle. This will prevent leading of the bore. This is NOT what you do with a springer air rifle, as the oil will produce dieseling.
I NEVER scrub the bore of my mirror polished BSA Lonestar .25 cal PCP air rifle. If you do, use a nylon brush, as air rifles use mild steel as it takes a much higher polish that ordnance steel. However, the mild steel is more easily damaged by harsh cleaning practices.
ALWAYS, keep some oil in the bore of a PCP air rifle unless it is the Benjamin or Sheridan air rifles that use brass barrels. The brass barrels will not lead foul or rust, and are best for those who don't like maintenance.
Ammonia cleaner gets out leading from PCP air rifle barrels, but see that it doesn't stay on anodized aluminum parts as it will affect the finish. It is also somewhat toxic to humans. By staying with a light coat of oil in the barrel and on the pellets, leading is eliminated in a PCP air rifle.
I only use a pull-through oiled patch in my PCP air rifle, and there are guys in England who NEVER clean their bore at all as long as they use oiled pellets and the accuracy stays constant.