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Posted: Tue May 13, 2008 3:59 pm
by DYI
i say go with 1/2" copper for chamber... then a high pressure pump or CO2- speaking of which can copper hold 800 PSI?
A chamber made solely of balsa wood could hold 800 psig if it was thick enough. If, however, what you meant was "can the commonly available Types M or L copper water pipe hold 800 psi?", then the answer is, still, yes. It is over the rating, but still nowhere near the burst pressure for M, and I believe it is actually below the rating for type K.

Posted: Tue May 13, 2008 4:03 pm
by JDP12
cool thanks DYI

Posted: Thu May 15, 2008 4:51 pm
by STHORNE
Ok people, Listen Up!!!

I have recently decided to change this from a "marble" rifle, to a "bb" rifle because you can reach higher velocity at the same pressure with a bb rather than a marble. Also, one of my bb guns broke and I have a perfectly good 2" long bb-barrel :D It's even rifled!!!

I threaded it externally so it can be exchangeable for different barrels.
everything is working good as far as the piston valve assembly, just need to get some parts welded at school tomorrow.

Ask if you don't get something and I can post a picture or two.
It's coming along :D :D :D Sooo exited!

Oh! I also got a bunch of stuff from the bb gun like a kick ass scope, a stock (kind of crappy so I'm still going with the homemade one), the pump, and some internal stuff (like springs, trigger assembly, etc.).

Posted: Thu May 15, 2008 5:40 pm
by FordGtMan
LOL will a 2 " long barrel fit your needs?your chamber is going to have to be really small lol

Posted: Thu May 15, 2008 5:41 pm
by STHORNE
I know its pretty short but it should be fine accuracy wise up to.... 50 yards. And I plan on making my chamber smaller so that will help too :wink:

Posted: Thu May 15, 2008 5:44 pm
by FordGtMan
Nice. it will all fit in that stock real nice now. You should make a high pressure three shot burst gun so if accuracy doesn't turn out good, you will have other bbs to compensate :)

Posted: Thu May 15, 2008 5:45 pm
by STHORNE
FordGtMan wrote:Nice. it will all fit in that stock real nice now. You should make a high pressure three shot burst gun so if accuracy doesn't turn out good, you will have other bbs to compensate :)
lol, maybe...I'm thinking about doing the high-pressure pump. I have all the supplies I need....

IDK, we'll see :wink: :?

Posted: Thu May 15, 2008 5:53 pm
by FordGtMan
So you are actually considering just having this gun used at 120 psi? It just wont be nearly to its full potential... :(
Lets make that "maybe" a "DEFIANTLY"

Posted: Thu May 15, 2008 5:59 pm
by STHORNE
lol, i know, that's why I'm debating whether or not to use the high-pressure pump.

You see, here are the arguments:

+compressor: Easy/faster fill up
-compressor: Low psi, long to start-up and not portable

+HP pump: higher pressures and portable
-HP pump: Long...everything

But all-in-all, I think the High Pressure pump is a winner, So attention everybody, I WILL BE USING A HIGH-PRESSURE PUMP!!! lol, I just shouted that and my mom was like, "Who the hell are you talking to?". lol :wink:

Posted: Thu May 15, 2008 6:01 pm
by FordGtMan
Hopefully she doesn't think you are talking to your girlfriend... :D If the chamber is going to be small as hell anyways, it wont take long at all to fill it right? How big of a chamber are you going to use?

Posted: Thu May 15, 2008 6:04 pm
by STHORNE
lol, no...not my girlfriend :oops:

um, for the chamber, I was thinking 1/2" copper pipe. About....eh...6-8" long.

What do you recommend? I would like to keep it below 9 but don't want it to be too long for pressurizing time purposes...

Posted: Thu May 15, 2008 6:07 pm
by FordGtMan
Dont think it would even matter much even if it was under 5 inches cause it would still be like a 15:1 ratio...lol :D

Posted: Thu May 15, 2008 6:11 pm
by STHORNE
lol, true. but it's all about powa. THE POWA!!! :director: :violent3: lol

Posted: Thu May 15, 2008 6:18 pm
by FordGtMan
Lol, i think you should just invest with a longer bb barrel and then use the 2" for a covert mini coaxial :). Only with extremely high pressure will you be getting power with a 2 " barrel. I mean, co2 guns use 800 psi and most only get around 400 fps, or are they regulated down a bit? either way, i say the longer barrel. :( :roll:

Posted: Thu May 15, 2008 6:20 pm
by bigbob12345
High pressure pumps do have disadvantages, many of them
1. They can be tricky to build depending on your exceperience with things like that
2. They are costly(ussually $60+, but i managed mine for about $50)
3. It takes a really long time to fill anywhere near a sizable chamber
4. If not made well they can be very unreliable and have a tendency to break(So make it servicable)Not saying that you are going to make it poorly there