science project help

[pariah1475]

I wanna do a science project that tests something to do with gas efficiency and porting of barrels, along the lines of: how does porting style A, B, or C compare to a non ported barrel and to each other.

My question is regulate how much pressure goes into each barrel and how do i measure how much is in each? Also any other ideas or reccomendations would be greatly appreciated. Also, I need help making symmetrical porting on a brass pipe, if you could help with that. Thanks!!

[Aranarth]

What level of science project is this? For a simple one, use output fps as your determining factor. If you want to make it even more complex, try to work on sound tonals from different areas around the barrels also, to analyze porting. Also, varying barrel lengths with the same amount of porting, and 2 piece barrels (which are almost always stepped, look into the step decreasing effective barrel lenght) might also be considered. And for some real good kudos, do your tests, and see if you can find data such as maybe what you can get from tk's dyno experiments to support your theory(ies).
-AranarthX

[pariah1475]

this is a high school level project, the fps will probably work.

i have a large problem though-making the barrels and fitting them to air, i thought i could drill the porting (?) then attach the barrel to the valve of a mag, as its hard to make the barrel attach to an actual gun. thx

[Redkey]

If I'm reading this correctly you're going to try make a barrel?

You'd be better off buying one of those snazzy 16" *sniper* barrels and then record the velocities at 16" at the proper pressure to shoot at 300 fps. Then chop off an inch and repeat the test without changing the guns firing pressure. Keep doing this until there is no barrel left. I'd measure at least 10 velocities at each barrel length. Then average the numbers and plot them vs barrel length.

If the barrel has porting you should plug it so it doesn't mess up your results, since cutting off 1" of ported barrel will be different than cutting off 1" of unported barrel.

This is simple, easy to do and will only cost you one barrel and some paint.