‘Hello, Terry. It’s Richard Lyons here. We met at this year’s British Shooting Show, and you gave me some really good advice on rifle choice, for which I thank you. My new gun came with a comprehensive spares package, and I’m sure I read in one of your articles about the need to keep all PCPs clean and free of grit, but I’m not absolutely certain of the reasoning behind this. Could I be cheeky and ask you to help me again, please?  

Thanks again. Richard.  

KNOW THYNE ENEMY 

Richard, I’m glad my advice on choosing a rifle helped you, and of course I’ll explain why it’s so vital to keep dirt and grit out of a PCP. Don’t worry, it’s all perfectly straightforward and easy to understand.  

Inside your new rifle, there’s a main firing valve which opens and closes to release the air required to power each shot. This open/close action takes a tiny fraction of a second to take place, but it relies entirely on the valve sealing perfectly each time.  

The same goes for all other sealed areas incorporated in the design of the rifle’s regulator, if it has one, and to a slightly lesser extent the seal between the loading probe and the breech, and within the charging mechanism. PCPs rely on specialist ‘O’ rings and other types of seal, and if they become scored or damaged in any way, it’s highly likely that they, and the components that depend on them, won’t function as intended. Dirt and grit can damage the surfaces of these seals, so it’s easy to see why we need to keep our PCPs actions free of such contaminants.  

PREVENTION IS ALWAYS BETTER 

Also, a particle of grit that lodges between a valve and its face can cause a major air leak, which can drain a PCP of its power source in a very few minutes. Fixing this, or any internal seal or valve malfunction, usually requires a full strip-down of the gun, and it’s obviously far better to prevent the grit doing damage in the first place, hence the ‘keep it clean’ policy.  

The good news is, it’s really easy to prevent dirt and grit from invading your PCP. Simply keep your charging connectors, magazines, ‘O’ rings and other seals in a clean container, such as a freezer bag or similar, and keep those charging connectors, mags and pellets away from mud and other likely sources of contamination when you’re using your rifle.  

There you go, Richard – now you know, mate, and you can help others understand why cleanliness is so important.  

All the best.