.12g BB just disapear when fired at 200psi and don't hit the target...

have a look hereal-xg wrote:With the 6mm barrel on my copper QEV launcher GGDT says they go supersonic but i always thought that just using air at normal temperatures wouldn't alow the projectiels to go so fast (but maybe because of dead volume ?)
hectmarr wrote:You have to make many weapons, because this field is long and short life
Just because some guns can go supersonic doesn't mean that yours will, it just means that it is possible.al-xg wrote:yay! im supersonic then !!!! wooohh
Ill be getting the parts for semi auto before next week so i might pick up the 6mm barrel again.
if you're referring to the Gamo, that doesn't count as an example because it's a spring piston rifle, since the air is compressed suddenly its temperature rises, also you have to consider the diesel effect of piston lubricant detonating in the chamber, which has been proved (by comparing airguns fired in a vacuum to those fired in a normal atmosphere) to be a significant contributor to spring airgun performance.potatoflinger wrote:A lot of high-end bb guns can go supersonic, one from Cabelas can go up to 1,600 fps, so it is possible that you could go supersonic.
GGDT is a good performance guide but it cannot be depended on for accurate velocity data, you can only gauge this with a chronograph - they're not that expensive, you can get a cheap one off e-bay for very little, or even make your own using two photo-diodes and a PC microphone cable, there's a very good how-to on jimmy's site.yay! im supersonic then !!!! wooohh
hectmarr wrote:You have to make many weapons, because this field is long and short life