How do PCP guns compare to multi-pumps?
By B.B. Pelletier
Precharged pneumatics (PCP) such as the S400 carbine from Air Arms are certainly popular these days. Can they be trusted? How do they stack up against a good old multi-pump pneumatic like the Benjamin 397 for reliability?
Three important differences between PCPs and multi-pumps
First, the modern PCP is built to a higher standard than the average multi-pump. More money goes into the materials in the gun, so it's bound to be better. They have precision barrels and carefully developed valves that control the air much more efficiently than most multi-pumps. Because they have to hold a lot of air in reserve, they are designed to do it. As long as they are always left charged, they seldom develop leaks. Multi-pumps would do better if their owners always left them with a pump of air in the reservoir, but because so few owners do that, they fail much sooner than they should.
Second, a PCP is not subjected to the stresses of constant pumping, which puts a strain on the receiver tube and often the barrel, as well. A PCP is filled and emptied without a lot of flexing of the gun.
Third, almost all PCPs are made from either steel or aircraft aluminum, where most multi-pumps are made of brass. These materials are stronger, yet the guns themselves are not subjected to the stress of pumping, so PCPs come out ahead.
Genuine problem areas
Where PCPs have problems are when their owners tinker with them and do unauthorized modifications. Many shooters who buy PCPs want to work on them, too, and quite often that leads to premature failures.
Another cause for concern is overfilling the reservoir. Everyone can count to 10, so a Crosman owner knows when he's crossing the line. For some reason, a few PCP owners haven't learned the lesson of valve lock, yet. I hear about shooters over-pressurizing their guns, then complaining that they're malfunctioning.
What if you combined the best features of multi-pumps & PCPs?
Decades ago, there were multi-pumps that shot more than one shot per fill. Benjamin had several, then there was the Vincent and, in the 1980s, a Korean-made gun called the Yewha. All these guns and others were multi-pumps that shot more then one shot per fill. They were hybrids - a combination of a multi-pump and a precharged gun. All of them were made of brass, not steel, yet they suffered no problems, despite being flexed by the pump mechanism AND having to store lots of high-pressure air.
A Vincent rifle that's lost all its finish. The rifle was pumped
70 times, then fired several shots before pumping again.
These guns proved the strength of the PCP concept. They DID have sealing problems, but that was due to the seals that were used at the time, not the design. A modern PCP is one of the most reliable airguns you can own, as long as you keep it filled and don't modify it.