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Airguns by Make and Model => Benjamin Airguns => Topic started by: benji397 on June 28, 2022, 08:18:41 PM

Title: New Benjamin 397 holds air
Post by: benji397 on June 28, 2022, 08:18:41 PM
This is practically new, bought back in December. Today I just discovered it will hold a little air starting at 3 pumps. I read several old posts from Avator, Longhunter and others about this and some suggested fixes. I did a quick investigation and found that there is some paint overspray in the tube where the Hammer travels but didn't do anything about that yet. When I first got the gun, I cleaned the paint from the barrel and compression tube but didn't think about paint being where the Hammer is. I'm guessing, hoping that will cure it. I just don't like the fact that it is holding air.
Title: Re: New Benjamin 397 holds air
Post by: DanD on June 29, 2022, 01:37:08 PM
You can try to use the air retention to your advantage and pump less on subsequent shots. For example, maybe your gun would shoot 700 fps on 7 pumps the 1st shot, but still make 700 fps on only 4 or 5 pumps for subsequent shots.
I have a C9A purposely setup like this with a debounced hammer. IIRC it makes around 630-650 fps on 6 pumps from empty, and continues to make that velocity on 3 pumps for subsequent shots. It's great for hunting, but those 3 pumps are pretty stiff for plinking.
Just a thought, but I totally get it if you prefer the thing to dump. Just shorten the exhaust valve spring a little (not too short or the gun won't cock) if cleaning the paint out of the hammer area doesn't fix it.
Have fun!