25MM Pneumatic Sniper Rifle

Step 5 The Bolt and Barrel Assembly

in this particular bolt assembly the barrel moves with the bolt which could cause accuracy problems if the bushing is not modified correctly. but anyway its a modified version of THIS. the first thing you need to do is attach a 14 inch long piece of 1.5", then use epoxy putty to attach it to a piece of wood. This will make it a lot easier to cut, then you need draw a box that is about 10 inches long (refer to the pictures if you are confused). this will be the line you cut along with the band saw after the box has been cut out you will need to cut off the last inch on each side where the epoxy was holding the pipe to the wood. after the excess has been cut off each side attach a 1.5" coupling to each side. next you will need to modify the 1.5" to 1" bushings so that a piece of pipe can be slide completely through them with relative ease. in a stock bushing there is a stopper at the end off the bushing that prevents pipe from going all the way through. this will need to be ground off with a dremel, you might also have to also slightly enlarge the 1" socket of the bushing also. after the bushing have been modified glue them into the 1.5" bushings. then take a1.5inch long piece of 1" PVC and glue it into the 1" male threaded adapter and insert it into one of the bushings (it doesn't matter which). then cut a small notch into one side off the end of the bolt assembly (this doesn't make much sense so just look at the picture)

now we must build the the actual bolt handle; it's one of the simpler pieces. it is a hose clamp with a hole drilled through it and a dowel held in place with a wood screw. it does take a bit a measuring and test fitting to get the hole in the right place, but its worth the time to get it right. after you have screwed the handle onto the clamp insert the barrel into the bushing then put the hose clamp on it loosely. now force the barrel as far back as it can go, you should notice that it can actually go into the other bushing and it is very important that it does. once this is complete, tighten the clamp onto the barrel very tightly.

note : you can make the barrel pretty much however long as you want it. mine was 2 and a half feet of 1" pipe

Comments

[mrfuzz]

When you fire the gun won't the compressed air just leek out of the breech loader?

[irwinner]

it does but only a little, not to the point where it effects performance much

[Country dude]

couldn't you improve the preformance by sanding down the end of the barrel smooth (the end inside the bolt), then were the barrel meats the back of the bolt assembly you could put an O ring in there. in tern would stop a fair bit of air from coming out

[amenard1]

I simple used some duct tape. It probably doesnt do as good of a job as an o ring but it does help seal it.

[blubberdubber]

Where can I get all the materials needed for this in the UK? I can't find PVC in particular.

[vermeu]

This sight is for real?

[CaseBoy]

would it be possible to do the same thing with a 1/2"barrel

[pufferboy]

how big is the whole gun in total length?