Update 1: Scroll down for original post and pictures
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After a few months, I finally updated this gun.
<img src="http://i94.photobucket.com/albums/l112/ ... 2/Full.jpg">
<img src="http://i94.photobucket.com/albums/l112/ ... Detail.jpg">
I didn't really plan to radically change this gun, but the failure of the pilot valve forced me to. I switched to a pressure washer trigger for a while, but it was too bulky and it required too much of a change to the pilot system for my liking. I found this new blowgun, which was very nice except for the face that the flow it provided was far from satisfactory.
This flow problem was remedied in two ways. First, a 1/4" QEV was added to the pilot system, which should have solved the problem by itself. I decided to try to use my new lathe to put two o-ring grooves on the piston. Just to emphasise how much easier a lathe makes o-ring grooves, in under 60 seconds I went from a plain cylinder to a piston with two o-ring grooves; I did not even have to measure and they worked flawlessly the first time...man this lathe is fun 8)
The final change I made was the exterior. The shiny copper, protected by the lacquer, looked great...until the copper started to dull. I am not sure what it did this (probably scratched the lacquer a bit), but it was not looking good. Besides, this gun looked more like a rifle than a spudgun, and I decided to paint it like a rifle. It got an OD finish, which I personally like. I am sure there will be many members who prefer the plain copper look; luckily, I am not one of them, and as the owner of the gun, that is what is important, right
All in all, I really like the changes. I even find the pilot system attractive, as bulky as it is; I like it more than the previous streamlined version. At this point, 6mm BB's have become inadequate. I lathed (yes
) down some bolts and used those, which were pretty nice, but I'm going to attempt some darts in the future. Definitely look for future updates to this gun, because I have some more ideas. Damage shots to come when I find out what type of ammo really maximizes the destructive potential of this launcher.More pictures:
<img src="http://i94.photobucket.com/albums/l112/ ... rDetal.jpg">
<img src="http://i94.photobucket.com/albums/l112/ ... ngView.jpg">
<img src="http://i94.photobucket.com/albums/l112/ ... erview.jpg">
<img src="http://i94.photobucket.com/albums/l112/ ... erview.jpg">
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Original Post
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Yes, I am calling it a sniper rifle, no it does not have a rifled barrel, yes you will need to deal with that.
After months of inactivity, I finally got my act together to build this.
<img src="http://i94.photobucket.com/albums/l112/ ... /Full1.jpg">
Specs:
-Chamber Volume = 3.97 cubic inches
-Barrel Volume = 1.72 cubic inches
-Chamber to Barrel Ratio = 2.31:1
The chamber is constructed of a 17" segment of 1/2" Type L copper tubing. The rest of the chamber and valve fittings using 1/2" tube fittings as well.
The barrel is made up of two parts. First there is the outer barrel, which is constructed of 1/4" Type L copper tubing and has an ID of .315". The inner barrel is aluminum tubing with an ID of .24, creating less than 0.004" difference between the intended projectile, airsoft BB's, and the barrel diameter. I originally had a steel barrel with an ID of 6mm; however, this proved to be too tight of a fit.
The piston is a small piece of 1/2" Delrin rod that I super glued a neoprene sealing face onto. I would take pictures, but it is so small and simple, it isn't worth it to take the gun apart to take a few lousy pictures.
This gun varies greatly from the other ones which I have built. Instead of focusing on power, I focused on other aspects instead. I could have included the 72" BB barrel that I had bought; however, this would have destroyed the usability and looks of the launcher, and thus it was excluded. Even with the focus off of performance, GGDT still predicts that at just around 140 PSI, a 0.12g BB will break 1,000 fps. Not spectacular, but solid performance for a launcher oriented away from power.
One feature of the launcher that I focused on were the ergonomics. I wanted the launcher to be very maneuverable, and this was accomplished through a very low weight and through a short overall length. The launcher is comfortable to hold due to the ergonomic trigger and the comfortable foam rubber protecting the chamber.
Aesthetics were another important aspect of this launcher. I used a street elbow to connect the valve to the chamber to streamline the launcher a bit. A fitting female adapter, which is a copper fitting that has a pipe on one end and a female adapter on the other, was used in place of a conventional female adapter, again to streamline the launcher. The copper was polished to a shiny finish, and coated with lacquer to protect the look.
I know a lot of you expect some videos, but I don't really have any ideas of what I can shoot to really portray the power of this guy.
In the meantime, here are some pictures:
<a href="http://s94.photobucket.com/albums/l112/ ... jpg">Valve Detail</a>
<a href="http://i94.photobucket.com/albums/l112/ ... jpg">Valve Detail 2</a>
<a href="http://i94.photobucket.com/albums/l112/ ... jpg">Pilot Valve and Main Valve</a>
<a href="http://i94.photobucket.com/albums/l112/ ... pg">Angled Shot</a>
<a href="http://i94.photobucket.com/albums/l112/ ... pg">Angled Shot</a>
I doubt you'll hit 1,000 fps at just 140 psi, but throw a shock pump in the mix and it will be more than possible.
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Hahaha. Give me a break, I've been working all day and after the first sip of the beer, the brain just goes to mush 
