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Posted: Sat Sep 12, 2009 1:55 am
by jackssmirkingrevenge
I like your "box'o'random crap" shooting setup

Posted: Sat Sep 12, 2009 2:58 am
by MrCrowley
Excuse me, but it's actually a well thought out backstop

Posted: Sat Sep 12, 2009 5:58 am
by Brian the brain
That is very impressive...How would it compare to...a firearm??
Posted: Sat Sep 12, 2009 6:08 am
by MrCrowley
Brian the brain wrote:That is very impressive...How would it compare to...a firearm??
Seems to be quicker than a Glock 17 and M9 Beretta handgun (on a quick google search, not really sure how accurate those numbers are and I do know energy and velocity change quite a bit depending on the bullet fired) and a bit more muzzle energy also.
BtB, you should think about making a hybrid. I know combustions are illegal over there, but same here and i'm firing this in a suburb. I imagine its not a whole lot louder than some of your very high pressure creations and is a lot easier than pumping up to 600PSI or using a fridge compressor.
Posted: Sat Sep 12, 2009 11:18 am
by jhalek90
I love the sound of that last shot.
Congrats mate!!! i am hoping to do the same very soon.(I may already have..... woot)
Posted: Mon Sep 14, 2009 1:16 am
by MrCrowley
Another video:
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Posted: Mon Sep 14, 2009 1:41 am
by jackssmirkingrevenge
Penetration seems a bit... underwhelming, I know that's a tought target but still. Any chance of adding at a tail to the bullet to ensure it strikes nose first?
Posted: Mon Sep 14, 2009 2:08 am
by MrCrowley
jackssmirkingrevenge wrote:Penetration seems a bit... underwhelming, I know that's a tought target but still. Any chance of adding at a tail to the bullet to ensure it strikes nose first?
Yeah I was a bit disappointed with penetration, maybe my sabot was a bit third world, only wrapped it in tissue paper with a bit of tape.
The steel ball-bearings were only penetrating 4cm as well. Mind you, for those shots the target wasn't held down or anything, so there's some loss energy there and the sabot again was only tissue paper.
But yeah, guess I can add a tail to the bullet, at those distances I didn't expect it to tumble so much. The bullets are originally tracer rounds (with little to no tracer compound left) so I could easily glue a tail inside the bullet, what do you recommend? Few pieces of string or such?
Now that i'm thinking about it, I probably can get the tracer compound to ignite with the hybrid, the bullet I fired I had previously ignited the compound with a blow torch.
Posted: Mon Sep 14, 2009 2:21 am
by Moonbogg
Cool, looks like it packs a punch. I'd love to see a little more distance between the cannon and the target.
Posted: Mon Sep 14, 2009 2:42 am
by MrCrowley
Moonbogg wrote:Cool, looks like it packs a punch. I'd love to see a little more distance between the cannon and the target.
Unfortunately, due to my location, I don't risk putting too much distance between target and barrel. Just across the street is a primary (elementary) school, plus i'm surrounded by houses.
Though if I ever get a chance to take it somewhere safe and secluded, I'll definitely put far more distance between barrel and target. I can't wait to get this thing out to somewhere as described above, hopefully I've found a metal golfball barrel by then!

Posted: Mon Sep 14, 2009 6:40 am
by jackssmirkingrevenge
MrCrowley wrote:Yeah I was a bit disappointed with penetration, maybe my sabot was a bit third world, only wrapped it in tissue paper with a bit of tape.
Pity, given the effort that's gone into the launcher.
But yeah, guess I can add a tail to the bullet, at those distances I didn't expect it to tumble so much. The bullets are originally tracer rounds (with little to no tracer compound left) so I could easily glue a tail inside the bullet, what do you recommend? Few pieces of string or such?
I don't thing string will cut it with a hybrid mix. Any chance of jamming the bullet in a length of 10mm O/D pipe?
Posted: Mon Sep 14, 2009 7:12 am
by MrCrowley
Pity, given the effort that's gone into the launcher.
At least i'm penetrating steel well
Just need to find some more cooking trays, i'm awaiting the 'inorganics' where everyone chucks their junk outside their house (fridge compressors, various targets and cannon materials are pretty common), but it's a few weeks away yet.
Any chance of jamming the bullet in a length of 10mm O/D pipe?
Got some 1/4" copper I could jam it in quite well. Should also fit inside my barrel.
Posted: Mon Sep 14, 2009 7:35 am
by THUNDERLORD
Try wire-nuts for the skirt part, There are sizes/types of pipe they fit snug.
A short bolt can be inserted through a hole (drilled or cut tip),
a few nuts threaded on front.
The bolt end can be sharpened too.
Field points for arrows should work for that too.
If there's a HVAC co. or many junk appliances often have a bunch connecting wires.
BTW, where I live, 10'ft of 1/2" metal thinwall EMT is like $1.3? (in USA),
Fits a certain Red wire nut perfectly! (plan to check the rigid stuff later)
Gave me a thought for the "most power contest" the other day...
But I am tilting towards a ginormous blow gun-dart design from a plastic soda bottle top (A&W root beer) and long rod...(

Giving away contest ideas).
Cool vid! It would have penetrated further if the wood had been supported, and like you mentioned More snug fit ammo with barrel, straighter shooting ammo. IMO. 8)
(Dropped in from my online job hunt for today).
Posted: Mon Sep 14, 2009 9:58 am
by Ragnarok
MrCrowley wrote: Just across the street is a primary (elementary) school
Not what I'd be using as a backstop...

Posted: Mon Sep 14, 2009 4:17 pm
by MrCrowley
Ragnarok wrote:MrCrowley wrote: Just across the street is a primary (elementary) school
Not what I'd be using as a backstop...

Well for the first shot (you might see in the video) is a backstop that consists of:
1 x sheet of metal
1 x sheet of 3/4" MDF
1 x sheet of 1/2" plywood
1 x layered towel
Previous shots have told me that if the projectiles went through this 4" thick wood, the towel would definitely stop it. Plus, I was shooting so close to the target I wouldn't be able to miss it.
On Subsequent shots, I removed the backstop when it became clear I wouldn't come close to penetrating all 4". At most, I penereated 4.5cm, just under 2".