SpudFiles

i have been trying to make a 1/4 inch diameter steel nail propel out of a 3/4 inch diameter pvc pipe efficently with very little blowby and what not. my first idea was a sabot but when i tired making a sabot it got kinda wierd sorta(not sure how to explain)

any way does anyone know a good way to make a 1/4 inch diameter nail go through 3/4 pvc pipe efficiently

and the ammo would hopefully be reusable because i don't want to keep buying steel nails and sawing the heads off

other question:

are removable sound suppressors illegal?

raptorforce wrote:are removable sound suppressors illegal?

In the US, any device that can be fitted to a firearm and reduce the sound signature by even 1 dB is illegal without a permit. The best online resource in this regard can be found >>here<<.

As to making a practical dart projectile, consider this:



It won't be reusable in that the fins won't survive the impact, but you can easily make a jig that will enable you to mass produce ammunition. The main advantage is that the sabot can be a simple cylinder without having to separate etc.

The problem with that design is that the tip is not supported and tends to be off center in the barrel.

irisher wrote:The problem with that design is that the tip is not supported and tends to be off center in the barrel.

.. hence the unfeasibly wide fins. Another alternative that's a bit more labout intensive would be to have a second set of fins, or simply shape the fins as shown below:

Equally, if the base of the fins was square with the axis of the core, then the simple acceleration of firing would line the nose up squarely in the centre.
Under the forces of a proper cannon, gravity's effect on the tip is pretty negligible.

Consider, cannons use forces that can accelerate projectiles to hundreds of m/s in barrels of a metre or two - in the same kind of distance, gravity will manage a lone few m/s. As such, the impulse of gravity is pretty easily ignored in internal ballistics.

For a couple of numbers, HEAL will puts an average ~335 newtons of force on a 20g spud slug - gravity, about a fifth of a newton. The force of the pressure in this particular case is about 1700 times greater than that of gravity. So, as you can see, considering gravity in internal ballistics is generally pretty moot.

Also, to get back to the original point, bear in mind the inverse is true - unsquare fins would send the round wildly cascading.

if you are onleay using it at close range just rap the base of the nail in tape very cheap and dosent matter if it gets trashed

My best advice would be to take a small piece of paper, and form a simple cone of it, and wrap the cone in ducttape, next cut off the tip of the cone so a nail can fit somewhat snugly through it, once that is done wrap a thin line of tape around the cone and nail infront of the cone to secure the nail ( the head of the nail will secure the back)

Next, use a section of your barrel to mark on the cone the right size, make a line all around the cone with a marker, and cut about 2 mm above it, to compensate for the thickness of the marker.

This does not last very long, mostly because it is hard to remove the nails from wood targets without tearing the cone, but it is a very effective, easy and quick to make dart for nails of almost any kind.

And as a plus, you dont have to cut off the heads of the nails

jackssmirkingrevenge wrote:

raptorforce wrote:are removable sound suppressors illegal?

As to making a practical dart projectile, consider this:

yea thats the problem i was trying to make a sabot of foam but the hardest part is to make it fit the barrel and thats kinda hard

jackssmirkingrevenge wrote:

irisher wrote:The problem with that design is that the tip is not supported and tends to be off center in the barrel.

.. hence the unfeasibly wide fins. Another alternative that's a bit more labout intensive would be to have a second set of fins, or simply shape the fins as shown below:

can you tell me someone who has made one of those because they look difficult to make

maggotman wrote:if you are onleay using it at close range just rap the base of the nail in tape very cheap and dosent matter if it gets trashed

i want the sabot to come off in flight hence the name sabot. because when it comes off there is less drag and weight

Mass is bad in internal ballistics and good in external, i.e. once the projectile leaves the barrel you don't want to be discarding weight. Of course, most sabots are worth discarding due to drag considerations anyway. You might try using copper or sharpened PVC pipe to cut the foam disc. If you use the barrel itself to cut the disc, you are guaranteed a perfect fit. Just press hard and rotate it, and it might work depending on the foam.

skyjive wrote:Mass is bad in internal ballistics and good in external, i.e. once the projectile leaves the barrel you don't want to be discarding weight. Of course, most sabots are worth discarding due to drag considerations anyway. You might try using copper or sharpened PVC pipe to cut the foam disc. If you use the barrel itself to cut the disc, you are guaranteed a perfect fit. Just press hard and rotate it, and it might work depending on the foam.

how do you sharpen pvc? what tool to do use

Its like a barrel knife for ramming in potatoes: just take a file and shave away the outer part of the muzzle, so that the inner edge of the pipe is sticking out farther than the outer edge, giving you a sharp foam-cutter that will cut exactly to barrel diameter.

raptorforce wrote:

skyjive wrote:Mass is bad in internal ballistics and good in external, i.e. once the projectile leaves the barrel you don't want to be discarding weight. Of course, most sabots are worth discarding due to drag considerations anyway. You might try using copper or sharpened PVC pipe to cut the foam disc. If you use the barrel itself to cut the disc, you are guaranteed a perfect fit. Just press hard and rotate it, and it might work depending on the foam.

how do you sharpen pvc? what tool to do use

I'm not sure spudding is your niche' my friend.

frankrede wrote:

raptorforce wrote:

skyjive wrote:Mass is bad in internal ballistics and good in external, i.e. once the projectile leaves the barrel you don't want to be discarding weight. Of course, most sabots are worth discarding due to drag considerations anyway. You might try using copper or sharpened PVC pipe to cut the foam disc. If you use the barrel itself to cut the disc, you are guaranteed a perfect fit. Just press hard and rotate it, and it might work depending on the foam.

how do you sharpen pvc? what tool to do use

I'm not sure spudding is your niche' my friend.

your right and wrong i dont use spuds and i never will because iam sorta poor as i must buy everything accessory that is not a necessity with my own money aka allowance but i dont get much allowance which is based on which chores i do and how hard and how long they take. so iam very limited to what to buy hence no spuds and why i ask the projectile to be reusable. but i do have a pneumatic cannon which i will post as soon as i get the ammo inconvenience sorted out

a little off topic