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| azneye |
 Posted: 02/18/2007 4:08 AM Post subject: barrel length |
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Private
Joined: 18 Feb 2007
Posts: 10
26.01 Spud Bux
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so i made my first pneumatic 6mm sniper out of 5/16" brakeline (i may post pics later
) buy my question is i bought a 40" length brakeline is it too much? ive been searching on wiki and seem to conclude most sniper barrels dont exceed 30" so should i cut the brakeline or just leave it as is? |
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| chaos |
| Posted: 02/18/2007 4:13 AM Post subject: |
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Brigadier General
Joined: 17 Jan 2007
Posts: 1222
913.08 Spud Bux
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| azneye |
| Posted: 02/18/2007 4:24 AM Post subject: |
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Private
Joined: 18 Feb 2007
Posts: 10
26.01 Spud Bux
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| 1" pvc about 21" in length |
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| chaos |
| Posted: 02/18/2007 6:55 AM Post subject: |
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Brigadier General
Joined: 17 Jan 2007
Posts: 1222
913.08 Spud Bux
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| dunno mate it should be ok i think im not to sure on these kinds of specs |
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| noname |
| Posted: 02/18/2007 11:28 AM Post subject: |
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Mr Vortex
Joined: 10 Apr 2006
Posts: 2509
2698.56 Spud Bux
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It really doesn't matter. The extra 9-10 inches will help get about 20 fps more in velocity, and might help the accuracy a little, but it won't do much more than that.
The gun sounds good, hurry up and finish it so you can post it! |
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| LGM |
| Posted: 02/18/2007 11:32 AM Post subject: |
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Captain
Joined: 22 Jan 2007
Posts: 318
195.39 Spud Bux
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| I would cut the barrel just for easy handling. |
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| garfield |
| Posted: 02/18/2007 13:06 PM Post subject: |
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Private
Joined: 15 Feb 2007
Posts: 15
0.50 Spud Bux
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| noname wrote: | It really doesn't matter. The extra 9-10 inches will help get about 20 fps more in velocity, and might help the accuracy a little, but it won't do much more than that.
The gun sounds good, hurry up and finish it so you can post it! |
i wouldent think that i would realy matter |
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| ElasticBandit |
| Posted: 02/18/2007 14:24 PM Post subject: |
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Private
Joined: 18 Feb 2007
Posts: 17
29.41 Spud Bux
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| I have my own question ... I've built the regular run-of-the-mill spud cannons before, nothing special, but I have an idea for a pneumatic cannon that is fashioned after a machine gun. So my question is, what's the shortest a barrel can be with it still being remotely accurate? and what relation will it have to be to the chamber? |
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| chaos |
| Posted: 02/18/2007 14:57 PM Post subject: |
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Brigadier General
Joined: 17 Jan 2007
Posts: 1222
913.08 Spud Bux
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you should start by checking if it has been discussed before also if it hasn't you can start a new topic make sure it's in the right section to 
peace
chaos |
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| frankrede |
| Posted: 02/18/2007 16:47 PM Post subject: |
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Sangheili
Joined: 20 Jul 2006
Posts: 2896
421.43 Spud Bux
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| azneye |
| Posted: 02/23/2007 22:29 PM Post subject: |
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Private
Joined: 18 Feb 2007
Posts: 10
26.01 Spud Bux
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okay so i left the barrel length the same but the accuracy is horrible not even 6 feet away and the airsoft bb's are shooting randomly, u think i should get better grade bb's i have .12g
btw i have a small kine ghetto bolt that i stick into a 1/2" pvc and its more accurate, (shooting from the shell), than the bb flying out of the brakeline |
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| judgment_arms |
| Posted: 02/23/2007 22:57 PM Post subject: |
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The Judge
Joined: 17 Oct 2006
Posts: 1216
1363.81 Spud Bux
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Bah, here’s what you need to do:
One, leave the barrel the same length, it can only help.
Two, you need to do something called “crowning” to the muzzle, take a ½” drill bit chuck it in to a drill, put tooth paste (yes I said tooth paste, Crest, Colgate, Great Value, what ever.) on the drill bit, run the drill BACKWARDS.
Push the drill bit up to the muzzle, as though you where trying to drill it out. (Make sure you are running the drill backwards) if the drill “catches” stop immediately or you’ll ruin the barrel. What you’re doing is putting a taper on the inside of the barrel, when the taper extends to the middle of the wall of the barrel stop, you’re done.
Three, you need to put the gun in a full length stock, that is a stock that extends all the way to the muzzle, in order to support the barrel.
Now it’s my turn for a question: what are you using for a valve? |
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| imjustpk |
| Posted: 02/23/2007 23:01 PM Post subject: |
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Corporal
Joined: 28 Jan 2007
Posts: 63
145.44 Spud Bux
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has anyone ever seen "myth busters"? they once had an air pressure gun that only worked at 80 psi, but they had such a large chamber volume that they made a barrel that was about 60-80 feet long and about 1/4-3/4 inch barrel, they shot hay out at about 250-300mph, then they shot piano wire out of it that went straight though a 2x4 and punctured a concrete wall
hows that for barrel length |
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| frankrede |
| Posted: 02/24/2007 17:49 PM Post subject: |
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Sangheili
Joined: 20 Jul 2006
Posts: 2896
421.43 Spud Bux
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| thats what a good C:B ratio will do |
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| lukemc |
| Posted: 03/07/2007 10:51 AM Post subject: |
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Colonel
Joined: 25 Feb 2007
Posts: 561
54.59 Spud Bux
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| the volume of the chamber to barrel ratio should be about 3:1 |
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