Valve Lock on CO2 Airguns in Extremely High Temperatures

Given the extremely high temperatures across the country, it's probably a good time for us all to remember about valve lock on C02 air rifles and the benefits of shooting in a nice, cool basement right now.

The QB78 airgun family - like all other C02-powered air rifles including the Crosman 160 - will suffer from valve lock when the gun reaches a temperature in the region of 90 - 95 degrees F.

Valve lock occurs due to the increased pressure of CO2 in the air rifle due to the effect of temperature. This increased pressure overcomes the strength of the hammer spring and prevents the valve from opening fully. The result is a significant drop in muzzle velocity. It seems like there's a sudden problem with the gun!

The good news is that this is a temporary phenomenon and that the gun will return to normal when its temperature drops. There's actually nothing wrong with the gun, it's just a natural result of the physical properties of CO2.

So, keep your QB78 - or any CO2-powered air rifle - in the shade whenever possible when shooting. Better still, shoot in a nice, cool basement range where the temperature is a lot lower: both you and the air rifle will be a lot happier...