AT4 project

[nemisissy]

Some of you recall the combustion style launcher I finished drawing up a few weeks ago. Only to realize I would not be able to use it, and make the BATF unhappy. So as a result I came up with this.
http://i1117.photobucket.com/albums/k600/nemisissy/AT4%20Project/at4.jpg

Its a completely Inline compression system using a 24oz CO2 bottle. Its going to generally do the same thing that you would expect, whatever is loaded inside the shell will leave the barrell going about 450 fps depending on what I want to pressurize the chamber to. The outer shell will be dressed up to look as similar to an AT4 as possible.

Any questions or suggestions are welcome. I will be taking and posting pictures of its construction as it goes along, which will probably begin next week.

Oh and I stumbled across someone who was trying to make a nerf rocket that would spray bb's on impact, but never got out of the basic planning stage. I am perfectly aware I would probably not be allowed to use this, but its worth building at least one. http://i1117.photobucket.com/albums/k600/nemisissy/AT4%20Project/prototyperocket1.jpg

[Dayton]

A 24 oz CO2 Tank will not fit inside a 3" pipe. You have to use a smaller one. 12oz, 9oz, and 4oz tanks fit well. I went with 4oz tanks in mine.

[nemisissy]

actually the design is slightly old, it is a 4" pipe. the true dimensions of an at4 is about 3.5"

[Dayton]

PVC 3" nominal pipe is 3.5" OD.

http://www.engineeringtoolbox.com/pvc-cpvc-pipes-dimensions-d_795.html

I used this website a lot during the design stage of mine. It has pressure ratings of different pipes, pipe sizes, etc. Very useful.

Also, ABS has the same OD dimensions, but ID dimensions are slightly different.