You are Unregistered, please register to use all of the features of The Slingshot Forum!    


Slingshot Forum - The Slingshot Channel Official Forum > The Slingshot Channel Videos > Crazy contraptions >

Big bore pneumatic hand cannon


Reply
 
LinkBack Thread Tools
Old 02-26-2017, 09:35 AM   #1
tomfreds66
Member
 
tomfreds66's Avatar
 
Join Date: Mar 2014
Location: Somewhere Naughty
Posts: 404
Liked 410 Times on 191 Posts
Likes Given: 16

Default Big bore pneumatic hand cannon

Have been playing around with my low pressure launcher concept experimenting with large bore pvc pipe barrels of 25mm and nearly 30mm. Tested a variety of projectiles both skirted and with sabots. These work really well are stable and accurate in testing. Only downside are hand finishing is required to suit each individual barrel and at any decent speed are fragile and single use only.
Glued together a shortish barrel of 30 inches with 4 inches of porting to reduce noise levels at higher pressures. Decided to test 25mm steel balls weighing around 60 grams. By using double patching in the larger bore I had a pseudo sabot projectile. This worked very well, easy and ammo is reusable. Barrel is muzzle loaded with makeshift ramrod, then screwed onto launcher for firing. Shooting with around 120 psi of pressure showed great promise, accuracy was very good with plenty of power.
Will post chrony speed results soon


Attached Images
File Type: jpg 20170226_154107.jpg (18.7 KB, 42 views)
File Type: jpg 20170226_154142.jpg (24.5 KB, 41 views)
File Type: jpg 20170226_155032.jpg (9.8 KB, 41 views)
File Type: jpg 20170226_154639.jpg (15.6 KB, 41 views)
File Type: jpg 20170226_154325.jpg (31.4 KB, 41 views)
File Type: jpg 20170226_154426.jpg (20.3 KB, 41 views)
File Type: jpg 20170226_154807.jpg (15.9 KB, 41 views)
tomfreds66 is offline  
2
People Like This 
Reply With Quote
Old 02-26-2017, 09:58 AM   #2
tomfreds66
Member
 
tomfreds66's Avatar
 
Join Date: Mar 2014
Location: Somewhere Naughty
Posts: 404
Liked 410 Times on 191 Posts
Likes Given: 16

Default

Test results far exceeded my expectations. Was only hoping for 250 fps ( 75 m / s ) and around 200 joules of energy with such a short barrel. Only took 140 psi of pressure to better this. Using my pump to it's limit got me close to 200 psi, a scary figure in a pvc vessel. The performance was outstanding. Speed was over 360 fps, and those big 60 gram balls were exceeding 350 joules ( 250 foot/pounds )of energy. Recoil was quite noticeable with a substantial kick.
Taped together a 38 inch barrel for comparison and limited myself to 120 psi pressure. This combination really showed potential topping 270 psi and 200 joules ( 150 foot/ pounds ) with ease. Almost did some penertration tests but the thought of those big balls richocheting back quickly killed that idea.


Attached Images
File Type: jpg 20170226_104214.jpg (28.2 KB, 39 views)
File Type: jpg 20170226_155251.jpg (15.9 KB, 40 views)
File Type: jpg 20170226_103815.jpg (24.3 KB, 39 views)
tomfreds66 is offline  
Conrad_Bern_Pickl Likes This 
Reply With Quote
Old 02-26-2017, 02:52 PM   #3
TheNewSlingshotGuy
AKA- "The Raccoon"
TSF_ADMIN.png
 
TheNewSlingshotGuy's Avatar
 
Join Date: Apr 2014
Location: Brooklyn, New York
Age: 18
Posts: 4,761
Liked 3878 Times on 2140 Posts
Likes Given: 7027

Default

I wanna see what this does to a watermelon, an old CRT monitor, a coconut, a 2L soda bottle, and some steel cans. Oh, and an AR500 armor plate....
__________________
When in doubt, C4. -Jamie Hyneman

What do we want?!! LOW FLYING AIRPLANE NOISES!!
When do we want em!??
NYEEEEOOOOOWWWW!!!!
TheNewSlingshotGuy is offline  
 
Reply With Quote
Old 04-24-2017, 01:40 AM   #4
Tracker
Junior Member
 
Join Date: Apr 2017
Posts: 3
Default

Like to see some footage of how you got on with it,I've been looking at the small metal cannisters the air pistols and soda streams use,one bloke used some as is ,just dropped one into a pipe with some sort of point as a firing pin at the bottom really simple and works much the same as a mortar
Tracker is offline  
 
Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
How big is too big? GunGuy New project ideas 55 03-19-2016 10:41 PM
Pneumatic Spear Launcher? JoergS Off Topic 22 09-16-2015 11:41 AM
Pneumatic Crossbow Jeb New project ideas 0 07-09-2015 10:01 AM
Sligshot review: Forking Good Catapults-Pocket Cannon DukaThe General Slingshot Discussions 1 02-26-2012 07:10 AM
Does anybody here build pneumatic potato cannons? smoke Off Topic 18 10-06-2011 05:00 PM