Page 12 of 16

Posted: Sat Aug 31, 2013 11:31 am
by mobile chernobyl
Jack - would you be willing to make a larger one? I'm just looking for the Delrin sleeve - I can make the metal portion - (Unless you can whip up something nice!)

The ID of my barrel is supposed to be 1.682" I don't happen to have it [anywhere] near me at the moment though haha.

Is that within your machine's capabilities? There would be a nice video log of their use!

Posted: Sat Aug 31, 2013 1:00 pm
by jackssmirkingrevenge
Unfortunately maximum swing over bed for the sherline is 1.496", I could make it on the mill and rotary table but the largest diameter delrin i have in stock is 1.57" and less than 2 weeks before moving is not the time to buy new materials :-/

Re: machined APFSDS projectiles

Posted: Thu Oct 31, 2013 8:29 am
by jackssmirkingrevenge
New tests from Demolition Ranch:

[youtube][/youtube]

Some wins, some fails, lots of fun :)

Re: machined APFSDS projectiles

Posted: Thu Oct 31, 2013 8:43 am
by POLAND_SPUD
Impressive. Seems that the better they look the worse they fly ;-)
Also I suspect you make them a little too long to increase mass but then CG is shifted too much ot the back. Aren't you the guy who posted all those things about velocity being crucial when it comes to penetration?

Ohh and next time ask them to add a link to your channel

Re: machined APFSDS projectiles

Posted: Thu Oct 31, 2013 8:50 am
by Labtecpower
HAHAAA told you! another miniboy :D :D

Re: machined APFSDS projectiles

Posted: Thu Oct 31, 2013 8:55 am
by jackssmirkingrevenge
They all have a CG ahead of CP so in theory they should fly straight. I think those that tumbled were either hitting the discarding sabots on exit, or the fins were broken in some way. I supplied some delrin disks to reinforce the base of the shot wad in order to help the fins survive but it doesn't seem they were used.

The first two he shot which were the last ones I made seemed pretty spot on though. Shame they are are too long to be loaded normally.

Image

He linked to my channel in the beginning.
HAHAAA told you! another miniboy :D :D
LOLOL true! I don't blame him though ;)

Re: machined APFSDS projectiles

Posted: Thu Oct 31, 2013 8:30 pm
by POLAND_SPUD
Obviously not ahead enough :-D
though still pretty impressive...

ohh and I know that he linked to it already but the more the better

Re: machined APFSDS projectiles

Posted: Fri Nov 01, 2013 9:22 am
by jackssmirkingrevenge
Also linked in the description ;)
POLAND_SPUD wrote:Obviously not ahead enough :-D
Ahead enough... but I'm pretty sure that on those that failed, the fins were either damaged or the projectile dug into the wad on acceleration, because the delrin base disks were not used.

Re: machined APFSDS projectiles

Posted: Sun Nov 03, 2013 8:39 pm
by dart guy
jsr have you ever seen the reloading components for a shot shell ? since you are in Canada see if you can find any shot shells and take them apart then after looking about the insides of the shell you may be able to figure out some possible problems, i know that most wads have a plastic spring like thing in the wad so you may have some problems with that.
of course i can always post a bunch of pics and stuff if you like, it is almost time to get ready for next year's shoot. :)

Re: machined APFSDS projectiles

Posted: Tue Nov 05, 2013 4:35 am
by jackssmirkingrevenge
I already had access to shotgun shells when I made the rounds :) hopefully next year I'll get my firearms license and get a shotgun of my own.

Re: machined APFSDS projectiles

Posted: Wed Nov 06, 2013 9:03 am
by jackssmirkingrevenge
[youtube][/youtube]

HAHAHA!

Screw you, steel plate!

Labtec, not everyone suffers from the miniboy effect ;)

Re: machined APFSDS projectiles

Posted: Wed Nov 06, 2013 11:47 am
by Labtecpower
HAHAA f*ck yes :D
That was exactly the result I was hoping for hehe
I shot one of those taps with exactly the same result, pierced both 12 mm alu and 8 mm steel without even losing the tip.
Great job on making the projectiles :)

Finally some encouraging results!

Re: machined APFSDS projectiles

Posted: Wed Nov 06, 2013 4:11 pm
by dart guy
JSR i think if you made a dart where the fins had a ratio like 1 turn per 12 inches it would fly better but it would still need some aluminum fins.

Re: machined APFSDS projectiles

Posted: Wed Nov 06, 2013 4:45 pm
by Labtecpower
Air doesn't behave as you expect it to at supersonic speeds, so having twisted fins will have very little effect on projectile stability I think.

Re: machined APFSDS projectiles

Posted: Wed Nov 06, 2013 4:47 pm
by dart guy
i was thinking something like it would spin it at a slowwer rate therefore increasing stability, his looked like it made 1 turn in one inch.