Classic and simple .25 cal 'sniper' rifle

[Doodmens]

Hello,

This is my first gun showcase and my third gun so far.

The workings are very simple, I've used a 22mm copper pipe as air tank, and a presta valve adaptor soldered into a stop at the end (see third picture). I use a bike pump to pressurize it. The 22mm connects to the A-port of the generic ebay quick exhaust valve, which I modified to allow this. I used a blue slider valve (also ebay) to pilot it, with some springs attached to it. The trigger mechanism is all wood, but it works reliably.

The barrel is a special 12mm hydraulic tube, polished inside and outside, and a inner diameter of 7mm. Because it's a hydraulics pipe, it was not calibrated on the inside diameter, so using 7.0 mm BB's isn't possible, but I find that 6.5mm with some toilet paper in front of it to prevent it from rolling out. Or just some big nails, which usually yield a lot more penetration power.
I mounted the scope on a hand-made dovetail rail. Scope was from ebay, about $5.

I made everything by hand, no power tools involved except a jigsaw for the rough shape and a cordless drill.
It works and especially handles way better than my previous gun, and is quite accurate (I hit a pea at 10m with a nail).
If you have any questions about how it works, or comments on what I've could done better, please post them below.

UPDATE:
Video of it in action. It was recorded with a potato, sorry for that. It's my friend firing and me cursing. Noone was harmed.

[youtube][/youtube]

[ToasT]

Looks tidy. Nice job on the stock. The solid barrel should help with its accuracy.

I find my builds are much less frustrating when I start with a projectile I can get lots of cheaply. If you add a detent to the barrel, with a bit of tuning you might be able to retain those BBs. A very small hole with some rubber pushed through may be able to hold it, but I say that with no experience.
I use a magnet on the outside of the barrel to hold steel BBs in place.

[Doodmens]

I have tried using a magnet, but the steel of the barrel is too thick for even the strongest magnets I could find. The best option is to place one of these https://www.kjmagnetics.com/proddetail.asp?prod=R621 magnetic washers between the beginning/end of the barrel and the fitting that screws into the QEV. Hope that makes sense.
The problem is, however, that I live in the Netherlands. See the picture below...

So far I haven't found any store that has this kind of thing in Europe even.

Hadn't thought about the rubber thingy yet, might give that a try in a later version.

[cammyd32]

Try searching for 'countersunk magnets' they are basically the same but there appears to be quite a large selection of them on ebay fairly cheap with free international shipping.

Otherwise, what you could do is simply file a notch into the barrel, doesn't need to go all the way through, but just enough so that a magnet is effective.

[Doodmens]

Thanks for the tip! Didn't find exactly what I was looking for, but came close.
I needed a 12mm washer with a 6mm hole, as thin as possible.
They did have 12mm washers, but the 4mm was the biggest hole, and I'm afraid that will decrease the air flow too much.
So I went with these:

http://www.ebay.com/itm/290961684174?_t ... EBIDX%3AIT

These are 10mm OD, 5mm ID and 1 mm thick. Just gotta line them up a bit and then it's ready to go!

About the filing, I tried that, couldn't get it to work still.

[Brian the brain]

Nice build!

If it's a muzzeloader...you could simply knock a small dent in it with a centerpunch just after the qev.
That should be enough to hold the ammo in place.