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Homemade Rifle

I need to know what psi to use.

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#1 CheeseNerfer

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Posted 29 March 2004 - 07:21 PM

Yeah I'm making a homemade nerf rifle. Pretty simpl: 1/2 in. barrel, bicycle pump, ball valve type thing. I might post about it once I've finished but my question is what psi I should use and what estimated distances i'll get with that.

Thanks
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#2 hellsangel

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Posted 30 March 2004 - 11:57 AM

Depends on the material your using. If your using pvc it should tell you what pressure that you should not exceed and stay a little lower than that pressure to prevent weakening in the pvc walls.
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#3 CheeseNerfer

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Posted 30 March 2004 - 04:13 PM

Yeah I know I think the maximum psi on the PVC i'm using is like 430 or something but I don't whant to actually hurt anybody with this. I was thinking about 600 ft. is about how long my block is so that would be pretty good...
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#4 THIRST

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Posted 30 March 2004 - 04:16 PM

Yeah I know I think the maximum psi on the PVC i'm using is like 430 or something but I don't whant to actually hurt anybody with this. I was thinking about 600 ft. is about how long my block is so that would be pretty good...


Your obviously not thinking clearly, because the dart would probobally blow up before it reaches 600 feet, depending on the type of dart your using. An average stefan isnt meant to be fired at 430 psi.

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#5 CheeseNerfer

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Posted 30 March 2004 - 04:20 PM

I don't want to use 430 psi that's my whole point what psi should I use for about 600 ft.
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#6 cxwq

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Posted 30 March 2004 - 04:22 PM

You can get 600 feet with a highly modified stefan, though it won't be accurate.

Of course, with the weight you'd need and that kind of velocity it would probably break bones.

You need to understand that the fundamental trade off in nerf is between distance/accuracy and safety. With a relatively lightweight (1/4" steel weight) stefan, you're just not going to get over 100' accurately or about 200' inaccurately. If you use a larger weight, you'll get better distance and more accuracy but the safety decreases. At some point you basically have a .5 caliber air rifle shooting metal slugs.
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#7 texmustache

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Posted 30 March 2004 - 07:59 PM

Yeah I know I think the maximum psi on the PVC i'm using is like 430 or something but I don't whant to actually hurt anybody with this. I was thinking about 600 ft. is about how long my block is so that would be pretty good...

Wait one second. You don't actually want to hurt anybody? You mean, if you fire it at somebody, you don't want to hurt them? Or what? But wait, you say you want it to fire 600 feet? Those are mutually exclusive goals, silly goose. By the way, how do you plan on getting it to 430 PSI with a manual pump? Can you really push 430 Pounds, with one arm (or leg)? I still think theres a fine line between nerf and air cannons, and that'd be crossing it.
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#8 ompa

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Posted 30 March 2004 - 08:13 PM

lol I'd bet anything that can go a good 400 will severely injure someone, I mean, some of the nerf gun mods already bruise, and the pressure isn't even nearly that high. I agree with tex, what you're describing is a literal air cannon. If you want to actually use a gun like that in a nerf war, I doubt anyone would want to play with you. I'd say MAX ranges of about 150-210 feet to avoid killing anyone.

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#9 CheeseNerfer

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Posted 30 March 2004 - 08:29 PM

Okay, well with a manual pump and no magazine it would take to long to fire in a nerf war anyway unless I climed a tree and just sniped people the whole time so that's out of the question. I guess because I don't want to get screwed for breaking my next door neighbors arm I'll consider around 100-150 ft. Which is more reasonable I guess. What would you guess the psi for that would be?
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#10 earl the bunny

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Posted 30 March 2004 - 08:40 PM

If you are going for 100-150 ft, I would probably pump your gun up to around 150 PSI. Although you shouldn't go that high if you are using a PVC ball valve (rated to 150 PSI). If you are using a PVC ball valve go to about 120-140 PSI

My gun can hold 400 PSI (brass ball valve) and I get around the ranges you are expecting with 150-160 PSI.

Edited by earl_the_bunny, 30 March 2004 - 08:41 PM.

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#11 Pineapple

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Posted 31 March 2004 - 08:37 PM

If you are going for 100-150 ft, I would probably pump your gun up to around 150 PSI. Although you shouldn't go that high if you are using a PVC ball valve (rated to 150 PSI). If you are using a PVC ball valve go to about 120-140 PSI

My gun can hold 400 PSI (brass ball valve) and I get around the ranges you are expecting with 150-160 PSI.

Okay, now, someone posted pressures, so now I can ask some questions myself;

earl_the_bunny; are there any "indicators" that cue you to the fact that the pressure is too high, primarily at the connecting points of your homemade (glued joints, threaded connections)? Has your homemade ever "blown" on you?

I used a 2" SCH40 PVC 'T' connector, endcaps, and small sections of tubing to make my airtank, and mostly couplings and connectors for the primary assembly; my thinking was to use the really thick walled stuff for air storage, and standard walled tubing for the (48") barrel. I made a 1 1/2" foam projectile shooter (like a really big nerf dart), and now I'm troubleshooting it too.

I used only 80 psi from my electric air compressor to initially test it, primarily because I wasn't sure where to baseline my operating pressures.

And about valves; I initially used a Hunter 24v solenoid operated irrigation valve; but wasn't happy with the results; at 80psi it made a "sea lion" noise and hurled the test dart (1 1/2 in. dia. foam, 8" long, with 1/2 PVC endcap for weight) about 30 feet. I may not be using enough voltage to snap the valve open. Or, I may be shortchanging myself regarding operating pressure.

cxwq; I'm curious; at what pressure did you test your BAMF homemade?

Continued good luck with your homemade, Cheese. This is actually becoming a pretty fun part of Nerfing.

-Piney-
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#12 cxwq

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Posted 31 March 2004 - 09:24 PM

Anything over 100psi is probably excessive. I used a cheap-ass bike frame pump that's probably not good for more than 90psi and I didn't push it that hard. I'd guestimate I put 60-80psi into the thing and with a properly weighted dart it would have been good for at least 150' flat*.

It made the 'sea lion' noise too <g>



Note: I didn't actually make any darts heavy enough to avoid serious spin out problems. With a 1/4" steel shot weighted stefan I was getting about 100' before it corkscrewed into the ground. Or a fence. Or a house. Or a tree. At 60-70' the dart had not slowed appreciably and was still moving fast enough to self-destruct if it hit something solid.
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#13 CheeseNerfer

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Posted 27 April 2004 - 09:44 PM

I know cxwq you hate it when we post on things that are old, but I've finally almost finished the rifle but the paint comes off sometimes and my friend broke off the handle, plus I ran out of PVC cement so I havent glued part of the tube and when firing can only get it up to about 20 psi without it leaking through the quickly applied tape.


pics coming very soon.

Edited by CheeseNerfer, 27 April 2004 - 09:44 PM.

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#14 racoon

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Posted 07 May 2004 - 12:41 AM

would you pretty please use punctuation and/or more whitspace and/or breathe once in a while during a sentence cuz this is annoying to read if you know what i mean especially if you like to change subjects 5x per line


1. It's leaking.
Duct tape is nice, but don't use it for pressures, especially not when the area is curved. Just get to a nearby DIY-store and get some more PVC glueing stuff. Don't settle for anything less than the best, unless you want your gun to get broken down even more than it is now.

2. The paint comes off.
Specs on the paint? Sure it's for PVC? Try first sanding it down so it's rougher, then apply primer, then reapply.

Edited by racoon, 07 May 2004 - 12:43 AM.

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#15 NinjZ

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Posted 07 May 2004 - 01:18 AM

wow you wanted 600ft!!?? just play paintball, atleast the projectiles would hurt less!!! the whole point to nerf ( atleast my freinds and I ) is the closer range you play at. It makes it much more fun and interesting in closer proximities. you can take more risks and do more fancey tactics and manuvering. my first x-bow mod can easily get 150 feet, and its collecting dust in my room. my second x-bow mod gets about 80-100 feet depending on the ammo I use and is optomized for total silence (from 15 feet away you wont hear it unless youre listening for it). Its a whole other style/type of play in closer ranges.
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