in this video i'm going to teach you how to make a semi-automatic air gun you need a qev and a sleeve valve i bought both of them on ebay for less than twenty dollars qav as you should know has a exhaust sport uh the pilot sport and the input a slid valve you have to check one has holes around it that's the exhaust which should goes to the parasport of your so what this lead valve does is it cut off the air supply while piloting the qeb so like this is charging the qeb chamber and when you pull it back it will fire the qeb and block the air input so now i'm going to show you this in action here i made a chamber fight just with pieces i have and here is a painful tank with a regulator i'm going to turn it on right now i'm using five bar on this so let's see i'm going to fire it the one modification you should do with the qeb is put a spring behind the piston as you can see i put inside it it will close the valve automatically after each shot so i won't waste too much air i should see if it work by push it see you can feel it that's done now if you show this again it will only have one bank each time because the charging won't push the piston to the front and there won't be air wasting out by coming out from the exhaust port see it's only the little waste that you got here when you reconnect the air source basically next i'm going to teach you how to make a blow forward bolt c so so so so now you have the blow forward bolts working we need to make a magazine i'm using a cooper tube slightly bigger than your barrel like this i just slid it down where the input and basically that's it so i have glued the magazine on the barrel using hot glue it should be you should use stronger things like epoxy or fiberglass reason now you need something to type this hole the best thing i found to use is come from the toothpaste is this unit the bb from here perfectly you just glue this right here on your magazine [Applause] now i have this fitting glue i just tap the hole end cap so you open this to reload then you close it ready to go once you have finished you should find out the exhaust port size of your qav and put a standard fitting on it so you can connect your kv it's ready you have now a semi-automatic air gun now let's hear if it works so you