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Posted: Wed Apr 08, 2009 11:11 am
by Fnord
Instead of scrapping the barrel haves, I'd save them for making some nice stainless daggers or something similar.
Tis a sad day when you see 'perfectly good' stainless in the scrap bin. :D

Also what did that shot sound like? Could you tell something was wrong immediately?

Posted: Wed Apr 08, 2009 10:58 pm
by Larda
I did get everything recorded on 3 cameras, 2 normal video-cameras +1 high speed.
But i am not sure if its allowed to show you on this forum because the the target was a moose head.
Before the failure i did two shoots with my darts , but it locks like the sabots is to weak to survive the extreme forces.
The first shoot with a hardened dart hit the steel plate and broke before it could penetrate but i suspect that the sabot disintegrated inside the barrel, The second shoot with a unhardened dart was even worse , the dart started to spin directly when it left the barrel and did hit the steel plate sideways with enough force to deform the projectile.
When i recovered the projectile i could see clear marks on the projectile both from the barrel walls and from when the brass burst disks hit the projectile.
So before i try the darts again i have to make some better "bullet proof" sabots.
And a bad video, i will try to post a better one later.
[youtube][/youtube]

Posted: Thu Apr 09, 2009 12:26 am
by jackssmirkingrevenge
Larda wrote:But I am not sure if it's allowed to show you on this forum because the the target was a moose head
:shock:

Presumably the said moose was already deceased?

Posted: Thu Apr 09, 2009 4:46 am
by Larda
Yes it was, it was donated by a college that did all the hunting and associated activities :wink:

Posted: Thu Apr 09, 2009 4:58 am
by jackssmirkingrevenge
I figured :)

Why do you insist on the bulged nose dart design? All APFSDS designs I've seen use straight walled bodies. How about this soviet design?

Image

The fins are the same diameter as the barrel for support, so you only need a small central sabot.

Posted: Thu Apr 09, 2009 5:03 am
by Larda
The main problem now is that the sabot is to weak and its both being hit by the burst disk fragments (3x of 0.5mm brass) and the extreme forces during acceleration.

Posted: Thu Apr 09, 2009 7:14 am
by rp181
Could a foam cylinder behind the projectile help?

Posted: Thu Apr 09, 2009 7:18 am
by psycix
Will break apart. I think you should consider a steel one.

Posted: Thu Apr 09, 2009 8:45 am
by Ragnarok
jackssmirkingrevenge wrote:Why do you insist on the bulged nose dart design?
Presumably to help bring forward it's centre of mass.

I'm convinced I've seen some of these pictures before... I can only assume it was in the chatroom.

Posted: Thu Apr 09, 2009 10:06 am
by Larda
Ragnarok: Exactly,, it was to forward it's centre of mass.
I don't know if its working but at least they are looking cool. :D
Yesterday i started working on a new GB barrel for the hybrid unfortunately i didn't have my real camera with med , only my mobile phone.
So sorry for the bad pictures.

Posted: Thu Apr 09, 2009 10:09 am
by jackssmirkingrevenge
Poor, poor golfballs... Looking forward to see them screaming past the speed of sound :D

Posted: Thu Apr 09, 2009 10:16 am
by Larda
I am hoping for (speed of sound)x2 :D

Posted: Thu Apr 09, 2009 10:41 am
by inonickname
Just what everybody wants,a golfball with brass chunks embedded in it traveling at mach 2 towards them!

I'd feel sorry for anything that gets shoved in that barrel..

Very nice, lets see if the golf balls hold up.

Posted: Thu Apr 09, 2009 10:42 am
by ALIHISGREAT
Larda wrote:I am hoping for (speed of sound)x2 :D
I think i speak for everyone when i say i want damage pics! :roll: :lol:

Posted: Thu Apr 09, 2009 10:49 am
by Ragnarok
Half surprised JSR didn't comment on "muzzle break" - he usually catches it. This is probably because he was thinking the same sort of thing as I was.

This was HOLY CRAP! - those pressures and that bore diameter? Heck, forget Mach 2, I'd be surprised if you weren't close on scraping Mach 3. I'd expect muzzle energies of 15000 ft-lbs or more.

My only real concerns are whether that barrel is up to containing the pressures - and whether the golf balls are going to deform horribly under pressure and jam in the barrel. Those forces and accelerations, you might see trouble.

But if it works - it'll be awesome to watch! :D