SpudFiles

The dart was actually a glass drill bit about 6mm in diameter, 'twas friggin' effective.

Video will come in ~24 hours, I want to see if I can do some more shots tomorrow/look for the dart and film its location relative to target.

Could it have struck the fence with minimal energy and just bounced off?

That's what i'm thinking as the sound is roughly 0.75s after the shot and the fence is roughly 20m behind the target. We're looking at sub-150fps for sure. I'm surprised the camera picked up the fence hitting sound and not it bouncing back on to the driveway if it didn't stick. Perhaps it landed on a small patch of dirt or the sound is actually a neighbour/my brother (who was painting down by the house) reacting to the sound of the shot dropping/hitting something.

edit:

The projectile penetrated all four layers of the target, which are spaced apart, with a perfect exit hole so I assume it was still stable in flight. But by my rough calculations, the projectile should have also collided with the driveway as my driveway slopes up relative to target location. My rough calculations had the projectile making contact with concrete ~1.5m from the fence; perhaps my estimate was off by that amount.

How did you stabilise the drill bit?

It was supported in the barrel with a pusher and some cotton balls but in flight it might have been stabilised by the glass drill bit head; which is like a spade bit. Though it seems unlikely:
http://www.aquariacentral.com/forums/at ... 1329036840

Edit:

Went up and had a look, couldn't find anything. It's a real mystery where the sound came from.

MrCrowley wrote:cotton ball

Kiwi tech



Y U NO USE PROPER SABOT?!

but in flight it might have been stabilised by the glass drill bit head; which is like a spade bit.

Only if the spade bit was at the rear...

Y U NO USE PROPER SABOT?!

Well the pusher had a hole half way through which accommodated the rear section of the bolt after the fins (as seen here), the cotton balls were merely used as a means of keeping the bolt relatively centred in the barrel. Judging by the results, I think the sabot worked perfectly (I got a perfect entry hole from 20' indicating the bolt was flying straight).

Only if the spade bit was at the rear...

Really? I thought the spade at the front would be better aerodynamically than at the rear. Anyway, I think the projectile may have bounced off the concrete and hit the fence and then bouncing off again.

MrCrowley wrote:Judging by the results, I think the sabot worked perfectly (I got a perfect entry hole from 20' indicating the bolt was flying straight).

We'll be the frickin' judges of that peeectures! videos!

Really? I thought the spade at the front would be better aerodynamically than at the rear. Anyway, I think the projectile may have bounced off the concrete and hit the fence and then bouncing off again.

The spade increases surface area, if it's pointing forward it moves the CP towards it, but likely does not make a corresponding difference in CG.

jackssmirkingrevenge wrote:We'll be the frickin' judges of that[/b] [/url] peeectures! videos!

Uploading as we speak: ~137minutes

edit: 'tis live here:
[youtube][/youtube]

I has tungsten!



Now I need a sabot and I need to get my hybrid working again

Been doing some aesthetic work, nothing new as far as functionality goes, I need to work out a sleek loading system, and I have to wait for the arrival of my street elbow for a better chamber layout

Labtecpower wrote:Now I need a sabot and I need to get my hybrid working again

How had it stopped?

Looking pretty good there LnL!

Labtecpower wrote:I has tungsten!



Now I need a sabot and I need to get my hybrid working again

I fear that those tungsten electrodes(hopefully pure, not ceriated ) might be unstable in flight. What kind of of sabot will you be making?

hybrid's working again

May have been caused by the cold or so..

and i'll have to look for a new backstop, 10 cms of newspaper and a cutting board were killed at only 7x

I'll only do short range shooting, not sure how i'm going to stabilize the welding rods yet.

and i'll have to look for a new backstop, 10 cms of newspaper and a cutting board were killed at only 7x

Unless you're trying to preserve your projectiles, low grade steel plate works fine as a backstop. I have a piece of 45mm plate which was presumably used as ballast in its past life for that purpose.

Concrete "patio stones" (slabs typically 30 - 60cm on a side and between 2 and 10 cm thick) also work well. If you have a box to toss them in, they also work after they're shattered...

ok pui...

Some preservation of my projectiles would be nice, so I'll get a steel plate with a thick layer of newspapers in front of it.
my launchers aren't strong enough to desintegrate teh projectile on impact, so that should be enough

thanks for your tip

ITWOST: A plumbing we will go...