Posted: Sat Feb 23, 2008 4:57 am
I bought myself a heavy duty floor pump today and now that I have a chrony that can be used with projectiles greater than 6mm. thought I'd dust off this project and do some velocity tests. All tests were done at 150psi:
28 gram 3/4" slug - 234 feet per second (53 ft/lbs)
6 gram glass marble - 447 feet per second (41 ft/lbs)
3 gram 12 gauge sabot - 496 feet per second (25 ft/lbs)
Performance figures are a tad lower than I was expecting, it doesn't seem to be performing as it used to. Even with 40 more psi than I was using before, the crack on firing certainly isn't as sharp as I remember it. Perhaps the piston's gummed up inside, but it's all sealed in epoxy now so I guess I'll never know
28 gram 3/4" slug - 234 feet per second (53 ft/lbs)
6 gram glass marble - 447 feet per second (41 ft/lbs)
3 gram 12 gauge sabot - 496 feet per second (25 ft/lbs)
Performance figures are a tad lower than I was expecting, it doesn't seem to be performing as it used to. Even with 40 more psi than I was using before, the crack on firing certainly isn't as sharp as I remember it. Perhaps the piston's gummed up inside, but it's all sealed in epoxy now so I guess I'll never know