i see what u mean now if only i had a lath cbf doing that with a drill [/quote]

what would help is keeping the same length but drilling a 5mm hole down about 75% of the way to act as a tail
through the projectile? or the barrel?

the semi-auto mechanism isn't working its not moving forward enough to cover the hole and the spring isn't reseting it so iv giving up for a while ...

Are you making your own projectiles or using something commercially available?

yes im cutting 6mm steel rod which is actually 6.3mm into 15-20mm lengths to use as slugs cheap and readily available. i cant get bbs as yet working on it though
would making them shorter or longer help?

also would ...

Where did your get that small sprinkler valve? Can you get it in America?
i got it from a Reece irrigation store not sure if u have the stores in America but an irrigation store would carry them i s pose.


I'm sure a rifled barrel would attract attention at customs, particularly in a place with ...

Air rifle barrels are usually short by spudgun standards, what you can do is have a long smoothbore barrel then graft the airgun barrel to the end of it, this way you get high acceleration and the benefits of rifling.

that sounds like a plan since iv already gone through the time and effort ...

i wish i made that fitting. i had someone else make it for me (:
made some progress on the slide now to let the glue set. boring

anyone know how to rifle a 6mm - 1/4inch I.D steel barrel or how to make a tool to do it?

finished modding the valve today it resets fairly quickly. and since i already have all the materials to make the slide i think i'll give it a go and see how it turns out.

i have already made a prototype of the piston valve but destroyed it because it didn't seal i have now realized i probably should have placed an o ring in the bondo/bodyfiller around the barrel for the piston to press against forming a seal.
ur 6 mm semi is some what of a piston valve anyway.
i ...

i haven't finished modding the valve so im unsure at this stage.
i may just make that cannon a bolt action/breach loader. but seeing the semi auto i had to have one.
your designs have brought light to one of my incomplete projects.

heres the plan.
making a semi auto mechanism for 6mm - 1/4inch projectiles using Clides slider design. the barrel and mechanism will be encased in pn18 22mm - 7/8inch pvc

i have made the chamber and am working on the sprinkler valve

my questions and concerns are:
if i release 150psi from the valve ...

piston valve about 18mm or .7 inch in diameter i think iv got it though
now to make it and see how it works

about 30-40 feet the cap is to light and not very aerodynamic i haven't realy tried modifying it though

have a look at http://www.speedytoys.com/shop/
wish i could buy one but i cant get them shipped to Australia

better one get an empty glue stick big or small drill a hole in the middle of the twisty thing at the bottom (this will also remove the central rod) you may also find the twisting bit will separate from the tube. a bit of glue will fix this :lol:
http://www.prangpower.com/shop/images/GlueSticks.gif ...

downloaded it very detailed to many realy im unsure of some of the options like seat diameter, vent diameter. but all i realy want to know is roughly how much bigger in volume should i make the chamber compared to the volume of the barrel?