Spring-piston guns.

[Mitchza89]

Hey lads,

I'm looking to make a spring-piston air pistol/rifle just for something different. I have a 5inx1/2in very stiff compression spring that I wanna use. Does anyone know of any spring guns that have been made on this site and posted on this site?

[Hubb]

I don't know of any on this site. Actually, I've never seen one of these homemade.

I do believe, however, I saw a post on the topic somewhere in these forums. Someone mentioned that it would be very difficult to control and would require some strong construction work.

Anyway, good luck with this and keep us updated. It is something I've been interested in for some time now. I'll search and let you know if I come up with anything.

[singularity]

<a href="http://www.boltsniper.com/"> here is a link</a> to a page on homemade spring piston guns, i don't think anyone has ever posted that type of gun here.

[Hubb]

Ahhh. I forgot about Boltsniper. He makes some fine work.

[Mitchza89]

Cheers lads, thanks alot for the help. I reckon this is going to be a hard gun to make but it'll be interesting on what sort of performance I'll get .

[Hawkeye]

I would try it in greatly simplified fashion. Cock it with a ramrod and perhaps have a barrel that unscrews to breech load it.
A cylinder that houses the spring with a strong sear to catch the piston would be simplest. Then you can eliminate the need to use a lever or pump to cock it.
Insert the ram rod down either the barrel or exit hole from the cylinder and bounce your weight down on it like a pump to cock it.
A bigger spring would likely help. Something that you can still compress with your body weight and a bit of bounce.

[Ragnarok]

I could give you a nice detailed description of what happened when I tried to make a springer...

... but it would suffice to say that I ripped a significant portion of the flesh off the side of my left fore finger off down most of the way to the bone.
It took two months to even heal to a reasonable degree, and now remains as ugly scarring down the outside of the finger which will stay that way until I'm dead and buried - or loose the finger in a gunfight, but I'm not one to throw out a working finger because it's taken some wear and tear.

You do not want to see the photos, trust me - let alone experience it first hand.
And do you know what's really funny? The bloody springer never worked.

Seriously, take this as a warning about the danger of materials under compression.

[jackssmirkingrevenge]

I would advise strongly against making a spring piston rifle - the forces involved require access to high quality metals and an engineering shop to work them with if you're going to have any measure of power, and even looking at the commercially available springers on the market, I've never seen one with more than 40 ft/lbs of energy, and the higher powered ones are very laborious to cock and very hard to fire accurately.

Pneumatics on the other hand, some of them exceed 1,000 ft/lbs and require much less heavy engineering. As far as a homemade spudguns are concerned, there's no contest in my opinion.

[SpudUke5]

Wow, thats harsh. How did that happen? If what JSR is true, then 40 pounds (or less) or force ripped off your skin to the bone. Elaborate on this because its interesting to me

[Mitchza89]

Hmm well thats definately answered my question I was checking out the spring nerf guns that Boltsniper has made and posted on his site. Wow his guns are impressive.....

[jackssmirkingrevenge]

Hmm well thats definately answered my question I was checking out the spring nerf guns that Boltsniper has made and posted on his site. Wow his guns are impressive.....

Very very much so but as powerful as a cat's sneeze, that's the trade-off.

[Ragnarok]

Wow, thats harsh. How did that happen? If what JSR is true, then 40 pounds (or less) or force ripped off your skin to the bone.

That would be 40 ft-lbs of muzzle energy, which has no relation to force (unless divided by distance)
The springs store more than that, and they release it very fast.

I was using an ill advised choice of spring, which was storing probably at least 100 J, possibly more. I wasn't particularly paying attention to what I was doing, and the whole piston slammed forwards catching part of my finger in the draw mechanism.
No problem I have had with compressed gas has been anywhere near as nasty.

The project was, needless to say, scrapped. I may later return, but I can't much see the point. As JSR said, there wasn't much power potential.

I'm more interested in a coilgun now anyway. Being electrocuted will be more fun (although I'm practically immune, I have astounding skin resistance), and electromagnets have difficulty trapping your finger.

[ALIHISGREAT]

How about using a spring for an air rifle hammer valve?

[MaxuS]

I have astounding skin resistance), and electromagnets have difficulty trapping your finger.

All people with ginger hair do, i would know, i am one.
Theres a reduced pain response to electroshock, but increased pain response to heat.

[Wombat]

Boltsniper just made a pretty impressive paintball gun. He posted it here-
http://nerfhaven.com/forums/index.php?showtopic=10118

Oh yeah, and I forgot to ask; what were you planning on shooting? Because if you wanted to just shoot airsoft bbs, a spring piston gun would work fine.