My GB Gun Plans

A place for general potato gun questions and discussions.
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MrCrowley
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Wed Jul 12, 2006 5:32 am

im going to make a pneumatic GB gun(over-under desgin) with a 1.5" barrell 140cm(55"?) long then a modded 1"sprinkler valve followed by a 10cm chamber 70cm long, do you think this is a good idea? how fast do you think it will shoot and how far? im a bit of a noob when it comes to ggdt i dnt understand all of it so if someone could do it for me on ggdt and tell me that would be great. any tips or suggestions welcome :D
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)DEMON(
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Wed Jul 12, 2006 5:38 am

It sounds simple and easy to make, it shouldn't take allot of time. Make sure to get pressure rated pvc. You could also have interchangible barrels for shooting various things. Your chamber will take a long time to pump up with a bike pump. You also posted two of the same topics so delete your other one.
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rna_duelers
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Wed Jul 12, 2006 6:14 am

Nice n simple,should shoot far but look out for hitting people that are 2km away..lol
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mark.f
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Wed Jul 12, 2006 7:47 am

If you're using a 1.5" pipe for a golfball barrel, that should mean it's thinwalled, with somewhere around 1.7" I.D.? What are you sleeving it in? I don't know U.K. standards so I'll just tell you that 2" SCH-80 will work, or any type of high-pressure 2" pipe in the U.K., (don't know exactly). If not, you can always just use standard 2" pipe and add spacers to the outside of the 1.5" pipe and slide it in there, and then seal with epoxy, like on Mr. Plow's CylBolt.

As for GGDT, (I had to convert your measurements, but I think I've been accurate...) with a 1.7" I.D. barrel, you would be getting muzzle velocities of around 264 feet per second. Adding another sprinkler valve to the equation for more flow, you would be getting velocities of around 353 feet per second.

You can't really calculate range in GGDT for golfballs becuase of their aerodynamic qualities. I can really just guess at their drag coeffecient and say that you would get range at around 646 feet, (215.3 yards).
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MrCrowley
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Wed Jul 12, 2006 9:36 pm

the barrel is something like 44mm inside dia, oh and demon i must of forgotten about that lol ill track it down and delete it.and its hard to find the right fittings in NZ for interchangeaable barrels and im a tad low on money so it might take to the end of the month as NZ pipe prices are "outta this world" LMFAO
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