SpudFiles

ok for my science project I'm gonna use an air cannon to shoot a metal slug at different materials then create the best possible "tank" armor from the materials I've tested.

the materials need to be easy to find and relatively cheap.
I'm thinking 10 materials, 3 thicknesses of each.
final armor I'm thinking should not exceed 3/4 inch thick.

materials to test (need ten) in thicknesses of 1/16, 2/16, 3/16 inch
-aluminum
-cardboard (hard kind)
-glass
-sand
-clay type 1
-clay type 2
-clay type 3
-plastic
-ply wood
-steel (or other hard type of metal)

^please tell me if you see anyting I should change (thickness, materials,ect...) I have access tomany types of clays at my house.

from doing research online I found that the average spike type anti-tank projectile weighs about 4.2 k/g and goes 1800 m/s at muzzle velocity
-how do I make this proportionit to what I can shoot with a spud gun (what psi for how heavy a projectile)

thats all I can think of for now...any responses are very much appriciated!

I would just eliminate the glass and cardboard they don't even stand a chance. And the clay would have to be pretty thick, think about how fagile it is i can drop it from 3 feet and it will shatter, no chance against a metal projectile flying even at 50 fps.

Just set up a porportion for the projectile. I think it will be alot even if you scale it down. lets see 4.2kg/1800 = x/350 Then x will be about .82 kg (for you american's thats 1.79 lbs). Im not good with pnumatics but you would have to have a substantial sized cannon.
Hope this helps.

how about a sheet steel sandwich with a filler like sand?

ya I will try that depending on the data...

my chamber is 12 in by 4 in diameter, any chance someone could how much psi it would take to get a 1.79 lb slug to have a muzzle velocity of 350 m/s?

I could tell you if you told me what size barrel it has

All i can recomend is the GGDT calculator in the spud wiki. Just input the guns data and your projectile and mess around with the psi till you can get it to the desired fps. Ummm... if your chamber is only 12 in I put it in the calc and i got a problem it might have to be bigger. I don't know though.

barrle, hmm... any size, hows about 1 inch?

Yea hayseed barrel size shouldn't matter if the projectile weight is kept the same.

could you recomend a chamber size... I've got alot of extra pipe 8)

pyromanic13 wrote:my chamber is 12 in by 4 in diameter, any chance someone could how much psi it would take to get a 1.79 lb slug to have a muzzle velocity of 350 m/s?

Holy Crap!

Why exactly do you need that kind of power?

It would take a helluva lot more than you should be putting in there, I'll tell you that much, unless you have a 20 meter barrel or so.

Pyromanic13, since that is your name, are you planning to shoot a home made grenate with that ? Did that once, so I can imagine.

I used GGDT. It says that a barrel of 13 lenght, using 3 inch diameter would be good. So, if you want a speed of 350 fps with such a small chamber, you need more than 2000 psi. Yes, two thousand !!

Try to get a bigger chamber, of ammo with lesser weight.

ok first,
are you talking about real tank armor? because none of those would do,even if clay did work it would be too heavy for a tank.
saladtosser made an excellent point with the sandwich idea,the best tank armor is reactive armor,what it does is it has a sheet of plastic explosives in between 2 armor plates and its like this all around the tank and when the shell hits the armor it blows up the PE(plastic explosives) and repels the shell and only makes a "dent" in the tank hull compared to a hole where the shell has gone through and most likely blowen up the ammo.

if your not talking about real tank armor i would sugest sandwiching wet clay with 3/16" steel making the sanwich,i remeber there is a way to keep clay wet and i think its to cut of it from the air so unless you made a 3/16" box and filled it with wet clay then weld it with no leaks im not sure how you could keep it wet,the idea is that the clay will help slow down the shell/bullet enough so it wont penetrate it will only make a dent or maybe even no dent at all,if the clay is dry it will simply shatter,but thats the best material i can see there that would absorb the bullet enough.

@POS: The original number was m/s, not fps. 350 m/s would be breaking the sound barrier.

Even with my UHAVAS system (designed to assist in breaking the sound barrier), you wouldn't do it with any reasonable size or pressure figures.

Nothing that you can create would stop a 1.8 lb slug at Mach 1.05

It's about 50kJ of muzzle energy, which in simple terms:

This is a washing machine. This is not the target - it's postioned 300 feet in front of the target (which happens to be a small mansion) to let us know when the spudgun has fired.
This is because we are all deaf from the combined effects of sonic booms and massive reports, so we need a visual marker.

I think you should do what saladtosser said.
But, a very effective tank armour would be an armour that makes the projectile richochet off.