There are several ways to decrease the volume, but, my favorite is to use a ball bearing that just fits inside of the valve spring. And, yes, it will show a difference between the number of pumps required to gain a given velocity. Just be aware that it also increases the strain on the pump assembly.
A sleeve inside the valve is the common method for decreasing volume.... Is it used from the factor in some Crosman guns....Bob
it 's small enough to allow the exhaust valve to open fully. Sorry I don't have any pics. I'm not much on taking them, and I don't have a spare valve laying around to demo.
Quote from: longhunter on April 23, 2017, 09:52:17 PMit 's small enough to allow the exhaust valve to open fully. Sorry I don't have any pics. I'm not much on taking them, and I don't have a spare valve laying around to demo.it doesn't bind the spring ? do you have an idea of the diameter of the bearing ? thankskj