Ive always wondered...

[EliteRetard]

Why not use a high explosive instead of gunpowder? Youd need a much smaller ammount of it for the same force/pressure thereby reducing the weight of the rounds. A plastic explosive is very stable and also waterproof (heck it can even burn safely), and has the potential to reduce complexity and increase reliability by using an electronic trigger instead of a mechanical one. Even if a handheld weapon wouldnt benefit, surely something like a tank or artillery could benefit.

And why not a smooth barrel, you get more force applied to the round...its more efficient. Yeah back when rounds were just balls it was innacurate, but today we have modern designs and technology that can stabilize a round. Maybe you could even use a simple spring fin design thats held down by the casing when being stored/loaded. The fins would deploy once the round was fired, and should be even more stable than a standard rifled round. And what about dimpling? It increases the range and accuracy of golf balls, could it not also apply to rounds?

Im not at all claiming to be an expert, which is why Im asking. Its something Ive thought about many times...and from what I know it seems to make allot of sense. But surely I cant be the only one whose thought of this, so theres got to be a reason it wouldnt work, right? Spare me all the techno jargon, if you really know the answer you should be able to explain it fairly simply (ie plastic explosives simply cost to much or something).

Or am I really onto something here?

 

[tcsenter]

Or am I really onto something here?

No. High explosives detonate, gun powder burns (vigorously). Two very different reactions.

Gun powder works by releasing gasses that can fill a volume roughly six times greater than the gun powder itself. The rapidly expanding gas is what propels the bullet/projectile down the barrel.

 

[Mike Gayner]

tcsenter is on the right track with the gun powder question. With your other point - I don't understand how you can think manufacturing bullets with tiny retractable fins is more efficient than using rifled barrels, which really have very little extra drag compared with a smooth bore anyway.

 

[tcsenter]

Other technical details I left out such as the rate of expansion/burning of gun powder relative to the length of the barrel, among others. You can have gun powder that burns too fast in longer barrels.

 

[EliteRetard]

So high explosives dont create pressure to propel a round? Interesting. Im not sure I understand the difference, how does a high explosive cause so much more damage if it doesnt have a pressure wave?

And as far as the barrel goes, Im not talking about the friction...the riffling in a barrel means allot of pressure can escape out around the projectile, by using a smooth barrel nothing can escape and the full force of the explosion is applied to the round. I really dont understand your comment about the fins...I gave that as an example of how you could stabilize a round in a smoooth bore, again it has nothing to do with friction.

I was thinking that fins might be more efficient at keeping a round stable than a simple spin created by a rifled barrel. So youd have the benefits of higher muzzle velocity from a smooth bore as well as a more accurate round. I could be wrong.

But there are other methods to stabilizing a round, even a simple concept like dimpling on a golf ball. It seems to me that with modern technology a round could be designed to be very stable/accurate without the need of the spin created by rifling, and therefore could benefit from the higher velocity smooth bore.

 

[Born2bwire]

The bullet either expands to fit the grooves or it is slightly oversized to a force fit to ensure a seal. In addition, the brass casing expands when the cartridge is fired to fill the chamber. All of this moves to create a hermetic seal that prevents any gases from escaping behind the casing or in front of the bullet. Without these seals, escaping gas is fairly noticeable. I had a safety lug break on my bolt in a rifle once which probably unseated the casing as I distinctly felt the blowback of escaping gases.

As for the sabot, this is already done in shotguns so the idea isn't foreign to arms designers. If you wanted higher muzzle velocity, you can always go for more powder. A lot of cartridges are not fully filled with powder and you will find a variety of muzzle velocities for a given cartridge. Another reason I can imagine with sabot is the problem with drift from wind. A bullet can easily drift inches or feet over its flight due to wind. I would imagine that the added cross-section of the fins, and the fact that they do not slice the wind as cleanly as a cylindrical body does at broadside, would exaceberate the problem.

 

[grrl]

As Born2bwire said, rounds for a rifled barrel are built to create a good seal, smoothbores are no more efficient in that respect, nor is the muzzle velocity significantly different. Also, modern rounds are already very stable/accurate. Spin may be a "simple" concept, but it makes for a very stable round and eliminates aerodynamic problems that fins can introduce.

 

[Mike Gayner]

WTF no gas escapes through the rifling. Do you have any experience with firearms? Have you seen how tiny the rifling groves are? And you understand that the round expands to fill the rifling, right?

 

[Mike Gayner]

So high explosives dont create pressure to propel a round? Interesting. Im not sure I understand the difference, how does a high explosive cause so much more damage if it doesnt have a pressure wave?

You don't want an explosion, you want a clean, predictable burn, exactly like in the engine of your car.

 

[amdhunter]

What are you planning to blow up?

 

[grrl]

This discussion on tanks might answer some of your questions.

http://www.abovetopsecret.com/forum/thread137597/pg1

 

[tcsenter]

So high explosives dont create pressure to propel a round? Interesting. Im not sure I understand the difference, how does a high explosive cause so much more damage if it doesnt have a pressure wave?

That's the problem. Explosives produce such an intense and uncontrolled pressure wave that it would just obliterate the bullet (and probably anything else inside the chamber or breech), because they convert/react their mass (mostly to heat) almost instantaneously relative to gun powder. You're not going to get something to 'ride' the primary pressure wave produced by an explosive and still be intact. That's why explosives are able to cut steel, concrete, and rock.

 

[tcsenter]

In addition, high explosives can't be ignited through ordinary means. It requires another explosive to set them off. e.g. you can throw RDX into a bon fire and it will just flagrate. I wouldn't do it on the off-chance it might explode, unless it were in a remote area and you could keep a safe distance from the fire. Explosives can become unexpectedly unstable due to age, bad storage conditions or repeated exposure to wide temperature deltas, contamination by other compounds during storage or production, deterioration of poor-quality additives or flawed composition/formulation.