Oh well. It was worth a thought! I suppose the only decent solution is to find projectiles that exactly match your barrel. (I'm not keen on sabots).

Edit: Hotwired, how was the glue for your gun? Any issues so far? Are you concerned about safety in the long term?

At face value I would say 945 fps is incorrect. It would simply not be possible for this gun design. Whether that's a calculation error, an error in measuring target distance, or something else - I am not sure as this is not my gun.

Hi guys. I have been in contact with Joe Blogs and he has sent me a short clip of his gun in action. I'm just uploading it to youtube and it should be up in a minute (I'll link you when it's ready). He also sent me a sound clip of it being shot at a 10m target, which I'm going to double-check for fi...

What do you all think of a well-sealed piston that sits in your pneumatic gun's barrel. It would theoretically be airtight, well lubricated and have some mechanism* to stop it launching out the front of your gun like the projectile. The projectile would sit in front of the piston. This would negate ...

Don't overcomplicate things with sabots due to people posting incorrect information. I have a 1 inch barrel pneumatic gun from which I often shoot water bombs. It will only work if you pour a fair bit of water down your barrel first and shake it all around with your hand over the end to lubricate th...

Yeah it does seem slow. I had imagined filling only a small container to a really high pressure, although that would take just as long as a larger tank to a relatively low pressure. Thanks for the info on the tanks. I'll have a look into high pressure piston valves. I'd like to see this all work out...

There's no need to swat me down with the legality of it all - The guns themselves are illegal where I live, and the environment is going to hell anyway. Has anyone else converted a fridge compressor into an air compressor? Can you comment on whether or not my idea would be feasible? I'll probably ne...

Hi. I just thought it could be interesting to design a gun based around a spent CO2 bottle and a copper barrel. As for the valve I'm undecided. (Actually, I may have posted about this a while ago) But I just thought, to get the best use out of it, one might use a fridge compressor to pump the CO2 ta...

My above post was in reference to frogy's questions. Regarding your question (Tyro) A smaller barrel will restrict airflow, but using a larger diameter barrel will allow the air to loose pressure much faster because of the increased volume. If you have a very long barrel with a small diameter, then ...

In my opinion, you can't go wrong with a big chamber if you have a decent sized air compressor. If all you have is a bike pump, I'd go along with the suggested length from the GGDT. To check for projectile range, click "Tools" (up the top), then "External Ballistics Calculator". If you tick the max ...

The tension in the spring causes the ball valve to snap open when it is not held in place by the trigger mechanism. This has the same effect as opening a ball valve normally, except it should open somewhat faster than if a feeble human like you or I were to try and open it quickly by hand. I really ...

Okay )DEMON(, I'll have a look into that. I would expect that's just marketing talk to convince people to buy more bottles for each gas they want to store, since in the end there's just a pressure acting from the inside and that's all that matters to the bottle. I'll still check it out thought becau...

Yeah I noticed some sort of plastic flow restrictor inside the brass thread... Regarding the tapered thread, do you mean the thread tapped into the bottle itself? Or on the brass connector? If you know anything about the thread tapped into the bottle itself, any info would be great. Then I could do ...

I just got 4 decent sized (~4cm by 5cm by 1.5cm) satchels of the stuff from a new piece of furnature. I put one in a cup of water and it started making a crackling noise. Judging from the Wikipedia article, I have the type that burts when it absorbs a lot of water. I can't really think of anything u...

I was discussing with a friend recently how I would like to make a smallish all-metal pneumatic gun, which could withstand higher pressures to account for it's size. He suggested I use a spent CO2 canister as the pressure chamber (As in, pump it up with air - no CO2 gas involved) I was thinking of a...