Why pyrodex should be ok with the batfe for use in spud guns

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
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Mon Oct 03, 2011 6:13 pm

Joe470 wrote:Have you seen a lot of plastic rifles lately? I doubt anyone can or would argue that a potato flying at 300 fps is a good weapon. Its a toy, like a BB gun, that could cause harm or even, in rare instances, death if used inappropriately.
A run of the mill plastic combustion spud gun will launch a 100g spud with about twice the muzzle kinetic energy of a 0.22 rifle. Slice the spud along the long axis (so it acts as a sabot) and insert a round lead slug and you've got something with more muzzle energy than a low end rifle.

What it is made of, and what it fires, really has little to do with the dangers involved. We've been lucky that the ATF doesn't appear to be concerned but that is really just luck.
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Mon Oct 03, 2011 6:22 pm

One thing that struck me about the original post....

The OP isn't half as clever as he thinks he is. He uses BP and Pyrodex interchangably. While it's true that this can (for the most part) be done in normal "primative" firearms it is because the burn properties of Pyrodex and BP are similar at high pressures.

The problem is that in a spud gun application the combustion will be happening at low pressure. Pyrodex burns at a much lower rate than BP at low pressures. That's why it's generally considered safer - because it has a low burn rate at low pressure.

So what?

Well, if you treat the two as equivelent and develop a gun using Pyrodex and then switch over the BP because "they're the same thing?" You've potentially set yourself up to die.

They are NOT the same thing and outside of the context of old school firearms they should NEVER be treated as the same thing.
Last edited by D_Hall on Tue Oct 04, 2011 12:43 am, edited 1 time in total.
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Mon Oct 03, 2011 7:47 pm

I wouldn't try it let mythbusters do it

That's a good way to die like the other guy said
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Tue Oct 04, 2011 12:31 am

A run of the mill plastic combustion spud gun will launch a 100g spud with about twice the muzzle kinetic energy of a 0.22 rifle. Slice the spud along the long axis (so it acts as a sabot) and insert a round lead slug and you've got something with more muzzle energy than a low end rifle.
The two last shots in the video below have about the muzzle energy of an AK47.

[youtube][/youtube]
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Tue Oct 04, 2011 5:23 pm

Labtecpower wrote:
A run of the mill plastic combustion spud gun will launch a 100g spud with about twice the muzzle kinetic energy of a 0.22 rifle. Slice the spud along the long axis (so it acts as a sabot) and insert a round lead slug and you've got something with more muzzle energy than a low end rifle.
The two last shots in the video below have about the muzzle energy of an AK47.

[youtube][/youtube]
Yes. Anything more complex than a "run of the mill combustion" will approach, or exceeed, the muzzle kinetic energy of a high power rifle.
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Joe470
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Sat Oct 08, 2011 3:08 am

Ok
So the reason we shouldnt talk about it is that its too easy.

I figured people thinking about solid propellant guns were thinking of projectile-rammed onto powder, in a tube called a cannon- OR
shotguns. Or primer in brass with powder and projectile, like... a cartridge thingy.

Muzzle loaders dont have air spaces. As far as golf balls being lethal at 400 fps... lets do the math... Im really really bad at math so help me.

A golf ball weighs about .05 kg. 10 M per Second would be .50 kg/M/s thats a half a newton. I dont know what 400 feet is in meters. I guess 300 feet to be roughly 100 meters? lets say 130 Mps. 6.5 newtons or so?

a 12 guage bean bag has simmilar weight and ballistics. Its less lethal.


I said OVER and over... dont build one of these things if you dont KNOW its legal. DONT fill it with powder, Basicly, dont make em at all.


As far as people making metal projectiles for plastic cannons... well, do so at your own risk. I get as much enjoyment out of vegetables, which are at least slightly less likely to kill someone. Hey, hi, how are ya? Ok... im going to either accidentally hit you with a tater, or this hunk of aluminum I cast in the basement after making a mold with foundry sand and an estes nose cone ... pick one.


You make black powder cannons? Good for you. I have no need for one. I have no need for ANYTHING that could be construed as a weapon.


(its not a toy)

When I got my bb gun, it was a toy. I guess dangerous things cant be toys. At least, we cant call them toys. Because someone might sue us or get hurt and blame us. I can hear it now... you said this gun is a toy... so I pointed it at a person... oh, i didnt hear you the ten thousand times you said not to point it at people... but I heard you say its a toy.


Let me put it another way. Its not a weapon. It could not be easily modified to be a weapon any more than a canoe paddle, a chain saw, a flare gun, or a bb gun. It has a limited amount of power. (that is... ahhh hemmmmmmm until you make metal projectiles. Taters tend to fall apart in the neighborhood of weapon velocities. Steel doesnt.)

It has a SPORTING PURPOSE. Just like other NON FIREARM marksmanship TOYS. like BB guns, and blow guns, and nerf guns, etc. the point of shooting potatoes isnt something sinister or malicious. Although you could vandalize things with them. (someone is going to say YOU CANT SAY THAT, BECAUSE IF SOMEONE SHOOTS OUT THEIR NEIGHBORS WINDOW AND SAYS THEY READ IT HERE THEN THEY'LL SHUT DOWN THIS WEBSITE)


Do you know what is even easier than a powder gun? A compressed air gun. Youre not worried about someone slamming 200 psi into a piece of sch 40 and toting it around til they hit the butterfly valve? talk about a bomb.... Ever drop a 2 liter on its cap? PVC is much more brittle than polyethylene.

I want to see someone who is LICENSED to do so, produce something I can buy at walmart. UL listed, whatever. I can buy a golfball launcher for an M4.



They are idiot proof? Spud guns are? Well, ive been called an idot alot just now. I didnt know about this site years ago. I didnt know about laws years ago. Have you ever seen a good movie, then watched it again with people who hadnt seen it... and when the good part is coming up you know but they dont... and you kind of get a kick out of their reactions...

I have learned from experience over the years. What im reading about here, with the hybrid guns, and the compressed air guns, the designs, the performance.... I thought of that, designed and built that, and dismissed that YEARS ago... name it, I built it, maybe more than once. I had a gun that used flash steam. Utter failure. I had an HHO gun... incredibly powerful. (way more powerful than solid fuel) I tinkered with trebuchets, Ive made things that launched arrows, bolts, balls, washers, rockets, and various fruits nuts and vegetables. Ive experimented with pykrete, parafin, polyurethane, and potters clay, balsa wood, baseball bats, bowling pins and empty cans of butane. and all of it was without help of any kind. Can I make a cannon? Anyone can make a cannon. Anyone who is up to no good, already knows how to make a cannon.

So, I kindof doubt ANYONE here is going to read my post, run out, and hurt themselves. And I wont post anymore threads about it here. There are other places. I was lieing anyways about them not being powerful... they are dmn powerful. They (in plastic) put any propane, hairspray, air, or hybrid gun to shame. to SHAME. in every way. For every reason. They are safer. (idiot proof?) if this is your hobby and you can honestly tell me you have never seen or heard of a clean out popping out after gobs of hairspray foul the threads, and burning the crap out of someone's hand, then youve never been to the madison regata because it happens to someone every time.

powder is safer. Powder is more predictable. Powder is more dangerous. Powder is where you move on to when you want real performance. Powder is more controllable. Powder is just as legal. Powder is not easier, in any way. At all.

IF I were allowed to talk about it I would. I would tell you all about steel wool and guitar strings, chirstmas lights and telescoping radio antennas. Id tell you how putting acetone on nitrocellulose dissolves it and makes it into a castable polymer which cures and dries not unlike wood putty, but burns like a guitar pick, billiard ball, or ping pong ball.
KNOWING those things used to get me labeled as a criminal or something. People always assume the worst. Let me assure you, the criminals have an unlimited supply of AK47s and land mines and C4.

And laws are magical. making a firecracker is illegal. Making a M-80 is illegal. Batfe describes them as a roll of quarters with a fuse sticking out... yeah, those things, theyre illegal. period.

But you can launch rockets that go thousands of feet into the air. You can make smoke bombs. You can even have 20lbs of HIGH EXPLOSIVES shipped to your door. No license, No background check.

Potato guns ARE dangerous. Powder makes them safer. The rules about discussing powder guns are good ones. Nobody should put plans on here. I didnt really... I said any combustion gun is basically already designed for it. But I didnt put the plans for the charges on here... I simply wondered if anyone would think that it is illegal. Because from what I have read, it shouldnt be. Thats all. I guarantee i dont deserve a darwin award. Im not too cocky, but I can pretty much guarantee if an object is as big as a cantaloupe, I can hit it every time within 100 yards. if its within 200 yds, the size of a basketball, I can hit it at least every 3rd shot standing, every shot mounted.
Incase youve been paying attention, yes... ive improved.
and incase you havent been... NO! IM NOT A CRIMINAL, NOR DO I PLAN TO BE. EVER.
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Sat Oct 08, 2011 3:20 am

As far as golf balls being lethal at 400 fps... lets do the math... Im really really bad at math so help me.

A golf ball weighs about .05 kg. 10 M per Second would be .50 kg/M/s thats a half a newton. I dont know what 400 feet is in meters. I guess 300 feet to be roughly 100 meters? lets say 130 Mps. 6.5 newtons or so?

a 12 guage bean bag has simmilar weight and ballistics. Its less lethal.
You're kidding, right? I'm not sure if you've seen a golf ball flying at 120 meter per second but I wouldn't doubt for a moment it has the potential of killing someone.

You are aware bean bag shotgun rounds have killed people, right? We are not arguing about the rates of lethality (despite you stating bean bags are less lethal), your original argument was that golf balls at 400fps can't be lethal.
I had an HHO gun... incredibly powerful
A water fuelled cannon*? :wink:
Now this guy definitely knows what he's doing :D

*I'm aware you actually mean to say oxyhydrogen but I understand that writing it as HHO simply describes water and isn't a scientific term.


Can't be bothered replying to the rest. I'm calling troll.

Edit:
As far as people making metal projectiles for plastic cannons... well, do so at your own risk. I get as much enjoyment out of vegetables, which are at least slightly less likely to kill someone. Hey, hi, how are ya? Ok... im going to either accidentally hit you with a tater, or this hunk of aluminum I cast in the basement after making a mold with foundry sand and an estes nose cone ... pick one.
Don't be an idiot, check down range for people. Use that brain of yours. It's unfair people like you get to have a some-what functioning brain while people lay brain dead in hospitals who wouldn't be ignorant enough to shoot vegetables without checking down range.
What im reading about here, with the hybrid guns, and the compressed air guns, the designs, the performance.... I thought of that, designed and built that, and dismissed that YEARS ago
What can be asserted without evidence can be dismissed without evidence. Dismissed.
Potato guns ARE dangerous. Powder makes them safer.
How? I don't see it?
Last edited by MrCrowley on Sat Oct 08, 2011 3:36 am, edited 2 times in total.
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Sat Oct 08, 2011 3:24 am

I think thats the longest post in spudfiles history.
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Sat Oct 08, 2011 3:25 am

Joe470 wrote: A golf ball weighs about .05 kg. 10 M per Second would be .50 kg/M/s thats a half a newton. I dont know what 400 feet is in meters. I guess 300 feet to be roughly 100 meters? lets say 130 Mps. 6.5 newtons or so?

a 12 guage bean bag has simmilar weight and ballistics. Its less lethal.
A 46 gram golf ball travelling at 400 fps has an energy of 250 ft/lbs and would go through a human skull like a frozen stick of butter through warm steel. Not "less" lethal, just lethal.
Potato guns ARE dangerous. Powder makes them safer. The rules about discussing powder guns are good ones. Nobody should put plans on here. I didnt really... I said any combustion gun is basically already designed for it. But I didnt put the plans for the charges on here... I simply wondered if anyone would think that it is illegal. Because from what I have read, it shouldnt be. Thats all. I guarantee i dont deserve a darwin award. Im not too cocky, but I can pretty much guarantee if an object is as big as a cantaloupe, I can hit it every time within 100 yards. if its within 200 yds, the size of a basketball, I can hit it at least every 3rd shot standing, every shot mounted.
Incase youve been paying attention, yes... ive improved.
and incase you havent been... NO! IM NOT A CRIMINAL, NOR DO I PLAN TO BE. EVER.
I don't think anyone can argue with the fact that powder burners are fun, relatively easy to set up, safe if well made and handled and with a lot of power potential - but ultimately, discussing them on this forum is a risk to its survival, and that's the bottom line.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Sat Oct 08, 2011 4:32 am

Ha.... Oxyhydrogen ( 'HHO' ) more powerful than powder? If we're talking energy/volume, from memory even oxy/propane beats oxyhydrogen... Provided the gasses arn't compressed, I'm pretty certain any solid fuel has them both thouroughly beat (though admittedly I haven't done the math to back it up). About the only things oxyhydrogen has going for it is the fact that it's got an extremely high energy/weight ratio (hence its use in rocket fuel) and a very fast burn speed (hence why it makes a nice loud bang).
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Sat Oct 08, 2011 4:51 am

Ok Joe, I frankly don't care about the fact that powder burners are safer, nor do I care for your opinion. But you've blatantly flouted the rules here. I couldn't give an airbourne intercourse that it's legal according to the BATFE<sup>1</sup>, it's not allowed here.

A forum has to be a dictatorship, it's owned by an individual (PCGuy), he sets the rules, you follow them or you leave.

Onto the science. I've used at least a .22lr shell worth of green dot in an old bic pen with a 5mm lead ball wadded too tightly. It held for more than a dozen shots, but does that mean it's safer than a combustion?

And regarding being burnt by combustions, no offence but it takes no skill bar basic motor functions to build a reliable combustion. Your build quality has no bearing on the inherent safety of a well built combustion.

That should do, apologies if backseat moderating isn't ok.

<sup>1</sup>I presume it's still the BATFE?
/sarcasm, /hyperbole
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Sat Oct 08, 2011 3:25 pm

Joe470 wrote:A golf ball weighs about .05 kg. 10 M per Second would be .50 kg/M/s thats a half a newton. I dont know what 400 feet is in meters. I guess 300 feet to be roughly 100 meters? lets say 130 Mps. 6.5 newtons or so?

a 12 guage bean bag has simmilar weight and ballistics. Its less lethal.
That's all of your post I had to read to conclude that you're utterly devoid of logic. Do you realize that a .22 rimfire cartridge has a muzzle energy of about .71N? I don't think there's any argument that they're potentially lethal.
Joe470 wrote: I didnt know about laws years ago.
Then please crawl back into your hole and stop causing trouble for the rest of the world.
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Sat Oct 08, 2011 5:45 pm

MrCrowley wrote:Can't be bothered replying to the rest. I'm calling troll.
I concur! Witch means I can delete it, lock it, report it to administration or leave it for more trolling type discussion.....Hmmmmm, what to do???

Did you really have to guess?
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