How safe is a PCP airgun?
By B.B. Pelletier
How safe is a PCP airgun? That's a good question, especially if you're thinking about buying one.
PCPs are the oldest of all airgun designs. Some are more than 400 years old and still in working condition. There are no spring guns that old to compare to. But, let's talk about the bad side of a PCP.
Has any PCP ever blown up?
I've heard rumors of this, but I've never seen real facts. I do suspect there have been some accidents because there are a lot of tinkerers in the world, and I have seen some scary stuff. Like the guy who took a brass CO2 airgun (runs on 900 psi CO2) and, without strengthening it in any way, turned it into a 3,000 psi PCP. If that gun blew up would that be a real accident or just stupidity's reward? But, for an unaltered factory airgun to blow up, a whole lot of unlikely things would have to go wrong.
There are also some safety regulations on our side. The Department of Transportation regulates pressure vessels in the U.S., and they require safety burst disks on any vessel greater than two inches outside diameter. That they do not require them for smaller vessels means they are inherently safe and don't present a great enough hazard to be concerned.
The one airgun that has a reservoir that qualifies for a burst disk, has it - the AirForce tank. To date, there has NEVER been a report of a burst disk failure in an AirForce air tank. If the tank's internal pressure were to rise too high, the burst disk is designed to pop harmlessly and release all the air inside. It might shock you if it happened, but there would be no danger of injury.
What about an air reservoir rusting out?
This is another persistent rumor I've never actually seen happen. People get hyper-concerned about moisture in the air they use to fill their guns, and these stories get started. But, a 300-year-old PCP that still has its original brazed iron reservoir in good condition is proof enough that a rust-out catastrophe will probably not happen soon.
How about a petroleum/air explosion?
This is a dangerous possibility when shooters lubricate with the wrong oils, but, once again, I have no evidence that an accident ever happened. Lubricate high-pressure air vessels with pure silicone, only - never with petroleum-based oil or grease.
Two real PCP accidents
The two accidents I know of happened within a few miles of each other. One was an experimenter who was pressure-testing a reservoir he had made. He should have used hydraulic oil, but he didn't know that and used air, instead. The reservoir distorted as he filled it and finally blew up. He suffered no injuries, thank goodness, and now he does all testing with hydraulic oil. The other incident was a rubber-covered air hose that blew out while I was filling my gun. The hose was aftermarket and NOT up to specs for PCP use. I learned my lesson without harm, and I'm passing it on to you.