machined APFSDS projectiles

[Labtecpower]

In theory faster spin rates should give better stability.
If you have a bicycle wheel lying around, give it a gentle spin, keep it in both hands and try to twist it. This will be pretty easy. Now give it a hard spin, and try to twist it. This will be much harder.
Spin stabilizing also gets less effective as projectile length increases.

[Gun Freak]

Awesome results!!! Congrats. Their high speed footage is amazing... Especially the one with the socket head screw.

[jackssmirkingrevenge]

HAHAA f*ck yes
That was exactly the result I was hoping for hehe

You should have seen the grin on my face when I first saw that hit

Especially the one with the socket head screw.

Not sure what the hell happened there could have been the hollow nose, or the fact that the stabilizing band I machined was causing a shock wave that prevented effective drag stabilisation.

[Labtecpower]

You should have seen the grin on my face when I first saw that hit

I think it was about the same as mine

I've fired projectiles similar to the one that spiraled through the air, with the same effect.
I used a golf ball taped to a cardboard tube, it flew about 500 meters, but it did so with a corkscrew effect

The projectile that got stuck in the plate was made with one of these cores:



I fired some from my hybrid, with the following result:



The point on the last projectile is flattened because I tried to get it out with a sledgehammer hehe

[Talk]

the round used in shot 5 flew like a radar guided missile

[dart guy]

jsr, you could try filling the socket with lead next time, it my help it, all bullets/ slugs do that spiral but some are less noticeable.

[Labtecpower]

jsr, you could try filling the socket with lead next time

Why would you want to do that?
The idea of those darts is to have the CG in the front.

[dart guy]

That would help because the socket is in the front.

[Labtecpower]

That would help because the socket is in the front.

My bad

[POLAND_SPUD]

Why not make them exactly like darts used on blowguns??

[jackssmirkingrevenge]

Why not make them exactly like darts used on blowguns??

Subcalibre means lower frontal area means lower drag means more velocity retained downrange.

[mako]

JSR, JSR, JSR!!
Having noticed that all your darts that look like they should fly perfectly are not doing so, took a closer look. They look like rockets, not bullets, so aerodynamics says they should fly nicely. But the one that pierced the steel plate had heavier METAL fins on the back.

That got me thinking. Are you taking into account the fact that lighter materiel accelerates more easily? On an arrow the light materiel slows the rear, making it stay straight. But an arrow ceases to accelerate after leaving the string. A gun still has expanding gas leaving the barrel when the bullet exits the muzzle.

This expanding gas could be accelerating your projectiles a little bit; if the acceleration is minor, then the heavy tip isn't moving much, but the light fins are easier to move, causing tumble. The heavier fins seemed to be more accurate, which seems to bear out my theory. The last bit of propellant is still trying to accelerate the round, but the fins are now harder to affect than the tip.

@Labtecpower. Instead of hammering on them, you could try putting them in the freezer or cold water. The shrinkage might be enough to remove them. It might also make them brittle, so watch out.

[POLAND_SPUD]

yeah, but testing is limited to 10 meters anyway

[mako]

@POLAND_SPUD. What has that got to do with it? As a matter of fact, the closer the target, the less time the fins have to correct the tumble. I'm saying that the last expansion of gas sort of pops the fins, causing a severe tumble.

[Talk]

I googled "Flight path of apfsds" and i found this, may it can help you guys

http://www.google.co.uk/url?sa=t&rct=j& ... ms&cad=rja

i also found these projectiles are being discussed on some weaponeer.net site