Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 68 users online :: 4 registered, 0 hidden and 64 guests


Most users ever online was 218 on Wed Dec 07, 2016 6:58 pm

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

old school air rifle

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
Sponsored 
  • Author
    Message

old school air rifle

Unread postAuthor: volta » Tue Apr 29, 2008 6:42 pm

i've been building combustion and simple pneumatic launchers for a while now. although, this is the first time i've posted in a spudding forum. i'm also an avid airgunner.theyre both great hobbies in their own aspect. no doubt, but i've had the idea of combining the two for a very long time. let me tell you what i'm picturing.

i basically want to make a .40 to .50 caliber, smoothbore, co-axle piston cannon small enough to be mounted (attractively and effectively!) in an air rifle stock. the chamber would be 3/4 inch thick. the chambers also have to be able to take fairly high pressures. since the volume of the chamber and length of the barrel will both be cut a little shorter than optimal, the high pressures will have to be used to achieve the fast, 450 fps velocity i would love to have.

the reason i am posting this here is because i have a few problems that i've run into during planning. the first is the trigger. i could use a blowgun, but that is very common and i dont think it would make a very good triger for a rifle/shotgun that i plan on being accurate. any ideas are appreciated on that. also i just wanted to know what everyone thought about making the chamber out of 3/4 inch pvc pipe and the barrel out of a .40 blowgun.

if i should have posted this in the "mini" section then i am sorry, having it moved to where it belongs mould be much appreciated.

thanks for listening. any comments or advice is also very much appreciated.

thanks, colt
  • 0


volta
Private
Private
 
Posts: 2
Joined: Tue Apr 29, 2008 5:40 pm
Reputation: 0

Unread postAuthor: jrrdw » Tue Apr 29, 2008 6:48 pm

Got any diagrams drawn up? Sounds very interesting. How would a blow gun make it inaccurite?

Welcome to Spudfiles.
  • 0

When life gives you lemons...throw them back they suck!
User avatar
jrrdw
Donating Moderator
Donating Moderator
 
Posts: 6540
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Country: United States (us)
Reputation: 25

Unread postAuthor: biggsauce » Tue Apr 29, 2008 6:57 pm

What pressure do you want to use? That may affect what materials you use for your chamber.

Sounds like a cool idea, do you pln on posting your other cannons?
  • 0

User avatar
biggsauce
Captain
Captain
 
Posts: 338
Joined: Thu Jun 07, 2007 9:42 pm
Reputation: 0

Re: old school air rifle

Unread postAuthor: Ragnarok » Tue Apr 29, 2008 7:12 pm

volta wrote:since the volume of the chamber and length of the barrel will both be cut a little shorter than optimal, the high pressures will have to be used to achieve the fast, 450 fps velocity i would love to have.

450 fps isn't particularly hard to achieve, pneumatic cannons have managed twice that in the past. It is easily possible, but it will depend on projectile weight, and to some extent on your chosen barrel length.

PVC pipe for the chamber will limit your options on pressure to some degree, but rated low diameter pipe is fairly hardy. Even then, it shouldn't be pushed too far - but a member known as JSR (Jackssmirkingrevenge) has pressurized such kinds of pipe to around 400 psi - take that with a pinch of salt, as not all types of pipe are the same.

My personal choice would be something around 1" copper - but then, I build everything from copper, so that's hardly surprising.

I haven't used many blowguns in my time, so I can't be much use, although many people will swear by them. Myself, my favourite trigger so far is a slide/sleeve valve, although they are a little pricey.

Now, you need to discard any ideas you have of these launchers being particularly accurate. If they're made well and use consistent ammunition, they can hit moderately sized targets consistently at fairly short ranges, but they are far from pin-point accurate.
Some of my launchers have shown good results on "accuracy", more than I originally hoped for when I made them, but still far from a rifle (be it a real one, or an air rifle)

By the way, this doesn't need to go in the Mini section. That's mostly reserved for launchers of "pocket-size" or close to that.
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Unread postAuthor: Gippeto » Tue Apr 29, 2008 7:25 pm

Ummm, I think this might be of help.? :wink:

http://www.spudfiles.com/forums/high-pr ... 12803.html

Edit #1 And this;

http://www.trackofthewolf.com/(S(nzh5ri ... vvgtsc1x45))/categories/tableList.aspx?catID=14&subID=142&styleID=483

Edit #2 :oops, you did say smooth bore didn't you. :oops:
  • 0

"It could be that the purpose of your life is to serve as a warning to others" – unknown

Liberalism is a mental disorder, reality is it's cure.
User avatar
Gippeto
Donating Member
Donating Member
 
Posts: 2394
Joined: Sat Jan 19, 2008 10:14 am
Location: The Great White North...Canada eh!
Reputation: 11

Unread postAuthor: volta » Tue Apr 29, 2008 8:04 pm

ragnarock, i know it will never be truly accurate like any of my airguns. i am merely trying to replacate what the old airguns achieved. and after all, they did have smooth bores and used very simple valves of low pressure as well. specifically i'd be happy being able to shoot an index card at 10 yards. aside from that the real idea was to make a shotgun. i think some small sised shot would wreak kavoc on cans if i can get it up to speed.

to everyone else, thanks. i appreciate the thoughts. i will be posting my cannons here pretty soon if you'd like.

gippeto, i'm definately going to send you a pm. lol that gun you made is very simular to what i want to make.
  • 0


volta
Private
Private
 
Posts: 2
Joined: Tue Apr 29, 2008 5:40 pm
Reputation: 0

Unread postAuthor: keep_it_real » Tue Apr 29, 2008 8:40 pm

This is how I set up my trigger (current project). It's actually modded for semi auto but you don't need to do that.
  • 0

Attachments
IMG_1379.jpg

keep_it_real
Captain
Captain
 
Posts: 320
Joined: Sat Dec 23, 2006 4:41 pm
Location: Bend, Oregon
Reputation: 0

Sponsored

Sponsor
 


Return to Pneumatic Cannon Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot]

Reputation System ©'