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High pressure nail dart construction for 3/4" copper

Unread postPosted: Thu Oct 08, 2009 12:34 pm
Author: boyntonstu
A nail with a paper tail is fine for a blow gun.

Add 400 psi and then what?

I was thinking of using both a nose cone and a tail cone to stabilize the nail in the center of the barrel.

How high in pressure have you shot paper tailed darts?

Is there an easier way to make nail darts for a 3/4" copper barrel?

Recommendations and your experience with nail darts would be appreciated.

BoyntonStu

Unread postPosted: Thu Oct 08, 2009 3:21 pm
Author: psycix
How high in pressure have you shot paper tailed darts?
Unless you are replacing paper tailed with a mass of duct-tape or otherwise fimly attached chunk of paper, it will unfold at very low pressures.

You don't need to use a tail cone as sabot. You might wanna consider some loose wadding behind the projectile.

Unread postPosted: Thu Oct 08, 2009 4:31 pm
Author: jrrdw
If you know anybody who goes through a lot of caulk tubes, get them to save the cut off tips for you. Then use them for support for your paper cones. At those pressures a nose cone just behind the tip of the dart will be more stable then a tail cone.

How do the fins on a dart receive energy?

Unread postPosted: Fri Oct 09, 2009 2:57 pm
Author: boyntonstu
We use wadding to make a fairly tight barrel seal in order to get the maximum power from expanding gasses within the barrel.

How do fins on a dart receive their energy?

It puzzles me.

Unread postPosted: Fri Oct 09, 2009 3:01 pm
Author: Hubb
I'm not too sure I understand what you're asking, but fins on a projectile just act to stabilize the round, not receive energy from the firing.

Unread postPosted: Fri Oct 09, 2009 3:29 pm
Author: boyntonstu
Hubb wrote:I'm not too sure I understand what you're asking, but fins on a projectile just act to stabilize the round, not receive energy from the firing.


The air gets around the fins.

How does the air push the projectile?

Unread postPosted: Fri Oct 09, 2009 3:40 pm
Author: Brian the brain
You can do two things...well three actually.

First: use a hollow dart and slide it over the barrel.

This means a good seal, but a lot of dead volume.

Second: Use a piece of foam as a sabot.

Third: use a reducer at the muzzle and a pin through the sabot.THe reducer should allow the fins to clear but it should trap the sabot.
The pin is where the hollow tail of the dart rests.

Voila..a silent launcher ( gas escapes slowly after the shot as sabot blocks outgoing air) and no need to go find the sabot.......

Unread postPosted: Fri Oct 09, 2009 8:06 pm
Author: spudtyrrant
4 actually you can also make a cone for stabilization like on blow dart guns

Unread postPosted: Sat Oct 10, 2009 1:23 am
Author: jackssmirkingrevenge

Magazine fed nail darts?

Unread postPosted: Sat Nov 14, 2009 2:13 pm
Author: boyntonstu
I have been thinking about how to handle nail darts for magazine feed.

Paper tube cartridges with gravity feed comes to mind.

Any ideas?

BoyntonStu

Unread postPosted: Sat Nov 14, 2009 3:22 pm
Author: MRR
That's hard to accomplish because the darts are pretty long. You would need some kind of breach that opens far enough to let the darts slide into the barrel and it has to be airtight when locked.

A mechanical cartridge system like this user built would be my construction of choice.
http://www.spudfiles.com/forums/deus-ex-machina-t7864.html

Unread postPosted: Fri Nov 20, 2009 11:51 am
Author: ThegunGuy
Spring fed works best. A magazine can be made with a piece of sheet metal a spring, a metal bar the size of the magazine you want, a hammer and a welding torch.

Nail Darts, Distance and accuracy?

Unread postPosted: Sat Nov 21, 2009 8:57 am
Author: boyntonstu
Until I take my nail dart gun to my friend's farm, I have no idea of how far it will shoot or how tight the grouping will be.

To whet my appetite, have you shot darts at long distances?

I am curious about the distance and accuracy I can expect to achieve with a nail dart.

BTW I can produce a nail dart tail in about 15 seconds using 0.020" paper, hot glue, and a plumb bob to wind the conical shape.

It is likely that the spiral wound paper tail and its .020" edge makes the dart spin.


(Like the seam on a baseball)

I wish that I had a high speed camera to record the spin.

Unread postPosted: Sat Nov 21, 2009 9:03 am
Author: inonickname
Well it depends on several factors such as size, density, length, launch velocity, sabot, conical tail or fins etc.

I find darts to normally be fairly accurate, though it will vary greatly as a function of length.

Unread postPosted: Sat Nov 21, 2009 10:32 am
Author: qwerty
Yeah, i agree with ino. Darts are the most accurate ammo i use and they go the furthest distance. Instead of using nail try upside down screws in the cone, they penetrate stuff nicely. I shot one right the way through a 3/4 pine board at 100psi.