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Posted: Fri Jun 10, 2011 5:46 pm
by irisher
ITWOST: I bent my APFSDS round today. :cry: I guess I have even more reason to go for a distance shot because it is useless for armor piercing now.

Posted: Fri Jun 10, 2011 6:05 pm
by DYI
ITWOST: If your APFSDS round bent, it was insufficiently hard.

Mine may only be APDS<sup>1</sup>...
Image

But you can hardly argue with the results:
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1: Ground point on broken HSS tap, polycarbonate sabot, total mass of round is 12.1g and mass of penetrator is 8g. Target plate is 5/8", backstop plate is 30mm.

Posted: Fri Jun 10, 2011 6:51 pm
by drex
It looks like its time to decommission my valves back plate, its starting to fatigue around the bolts.
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I hoped this aluminum washer would have evend out the pressure from the bolts enugh, but I guess I was wrong :roll:
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I'm going to make a new one out of aluminum and do a whole bunch of other improvements to the gun.

Posted: Fri Jun 10, 2011 7:02 pm
by ramses
DYI wrote:Mine may only be APDS<sup>
But you can hardly argue with the results:
That's glorious!

What diameter was the projectile? Is that an aluminum sabot? I'm assuming you did this with your Al+H2O experiments.

Posted: Fri Jun 10, 2011 8:03 pm
by DYI
What diameter was the projectile? Is that an aluminum sabot? I'm assuming you did this with your Al+H2O experiments.
1: 6mm
2: Yes. Transparent aluminum...
3: You assume incorrectly. Just a little hybrid I use as an impact test rig/precision sledgehammer.

Posted: Fri Jun 10, 2011 9:11 pm
by ramses
DYI wrote:1: 6mm
Okay, thanks. Was that bore diameter or projectile diameter?
DYI wrote:2: Yes. Transparent aluminum...
Sorry, it looked shiny and opaque to me.
DYI wrote:3: You assume incorrectly. Just a little hybrid I use as an
impact test rig/precision sledgehammer.
Seriously!? Details are a necessity at this point.

Posted: Fri Jun 10, 2011 9:23 pm
by inonickname
ramses wrote:
DYI wrote:1: 6mm
Okay, thanks. Was that bore diameter or projectile diameter?
DYI wrote:2: Yes. Transparent aluminum...
Sorry, it looked shiny and opaque to me.
DYI wrote:3: You assume incorrectly. Just a little hybrid I use as an
impact test rig/precision sledgehammer.
Seriously!? Details are a necessity at this point.
http://en.wikipedia.org/wiki/Sarcasm

Posted: Sat Jun 11, 2011 2:55 am
by jackssmirkingrevenge
DYI wrote:2: Yes. Transparent aluminum...
:D :D :D

Fantastic penetration!

Posted: Sat Jun 11, 2011 12:11 pm
by Fnord
DYI, do you have any estimate on the muzzle energy of that shot?

JSR, the guy in your avatar is holding that grinder at a horrible angle in terms of kick-back. Also I find it kind of inappropriate considering your recent technological acquisitions.

Posted: Sat Jun 11, 2011 12:16 pm
by jackssmirkingrevenge
Fnord wrote:JSR, the guy in your avatar is holding that grinder at a horrible angle in terms of kick-back. Also I find it kind of inappropriate considering your recent technological acquisitions.
He's sharpening a cutting tool, take it up with Labtecpower ;)

Posted: Sat Jun 11, 2011 12:21 pm
by Labtecpower
I would like to see the mini hybrid you used for that shot!

@fnord: Don't insult my "close enough grinder guy"! :D he's even wearing safety glasses!

Image

Posted: Sat Jun 11, 2011 6:21 pm
by DYI
Just to clarify, it was done with a small hybrid, not an electric gun. The post showing the result clearly stated that the sabot was polycarbonate. The round was fired from a 0.569" barrel 84" long, and the broken tap that the steel core was made of was 1/4" (with a 6mm shaft diameter). HGDT estimated a muzzle speed around 550m/s, and considering that the SOS in the propellant gas was, in this case, ~1250m/s, I'm comfortable claiming an actual muzzle speed of at least 450m/s, for at least 1.2kJ muzzle energy (which I must stress doesn't mean an awful lot at such low speeds).

Posted: Sat Jun 11, 2011 7:51 pm
by ramses
Thanks for the details DYI. I still don't see where you said it was a polycarbonate sabot before.

I was thinking the same thing about the grinder guy and wearing safety glasses.

Angle grinders do sharpen tool bits very quickly. Like, fast enough to put positive rake on a parting tool in a tiny fraction of a second. Especially with a 60 grit wheel...

Posted: Sat Jun 11, 2011 8:00 pm
by MrCrowley
ramses wrote:Thanks for the details DYI. I still don't see where you said it was a polycarbonate sabot before.
Ground point on broken HSS tap, polycarbonate sabot, total mass of round is 12.1g and mass of penetrator is 8g. Target plate is 5/8", backstop plate is 30mm.
In smaller font below the last picture in his post. In your defence, there is some strange rule banning the use of any font smaller than 'Normal' and people tend to miss writing below a string of pictures as your mind probably reads over it as a member's signature and doesn't pay any attention.

Edit: After seeing DYI's results, I really wish I had some steel plate to shoot. With a good sabot and similar projectile to that of DYI's, it would be interesting what I could shoot through with a 48mm bore barrel hybrid

Posted: Sat Jun 11, 2011 8:09 pm
by Gun Freak
MrCrowley wrote: it would be interesting what I could shoot through with a 48mm bore barrel hybrid
Thats for sure... There's all this talk about firing specialized projectiles out big bore hybrids then barely anyone does it... I wanna see a video, damage, possibly some high speed footage if possible.