sumatrashooter
02-16-2010, 10:08 PM
I took my air powered arsenal to the camp this weekend. I noticed that the Sumatra looked like it had leaked a little. Thinking it was odd that it only leaked 100psi in 3 months I pumped it back up. Well, I went and hunted a nutria we'd seen near our dock. Well, while freezing my butt off I noticed it had leaked out 100psi in about an hour. Now I was mad! Fearing my gun wouldn't even have enough pressure to shoot if I did see that varmint within the next hour or so, I was about to call it quits and cancel the hunt. I didn't, and after not seeing him I went back up to the house. I put it in the corner mad as all get up. A couple of hours later I grabbed it and went to refill it and glanced at the gauge. It went BACK UP to its pre-leak air pressure. Ok.....my gun leaks and then refills itself. Not exactly.
What I finally discovered had happened was that I had filled it up in a 70 degree house. Well, it's cold outside and a blue northern blew through while I was outside and the temp dropped 20 degrees in an hour. Well, when air gets colder the pressure drops. When it warms up, it increases. What I was witnessing wasn't air leaking, it was the well known phenomena that hot air increases pressure and cold air decreases it.
So no, my Sumatra wasn't leaking at all. It was simply a slight air pressure change (about 100psi) with the temp difference. I would say that means we must be careful if we refill outside in the ice cold right up to the limit of the gun, that it will go up when we bring it in the house.
What I finally discovered had happened was that I had filled it up in a 70 degree house. Well, it's cold outside and a blue northern blew through while I was outside and the temp dropped 20 degrees in an hour. Well, when air gets colder the pressure drops. When it warms up, it increases. What I was witnessing wasn't air leaking, it was the well known phenomena that hot air increases pressure and cold air decreases it.
So no, my Sumatra wasn't leaking at all. It was simply a slight air pressure change (about 100psi) with the temp difference. I would say that means we must be careful if we refill outside in the ice cold right up to the limit of the gun, that it will go up when we bring it in the house.