Comments on: .50 BMG Flechette rifle

By: Lcpl. Budd

Lcpl. Budd — Sat, 07 Mar 2009 11:07:41 +0000

They’ve got one of these at MCRD (Marine Corps Recruit Depot) San Diego in the museum. It’s .55 caliber, was used in WWII (been almost 1.5 years since I visited the museum, but I’m fairly sure it was WWII) by the British, and was also known as “The Boy’s Gun.”

No DU (obviously). If memory serves, it was used up to 550 meters in an anti-tank.
Don’t remember if the total number produced was specified by the museum, but 12 doesn’t sound unreasonable, as the weapon was not widely used.

By: Steve

Steve — Wed, 25 Feb 2009 19:33:49 +0000

Well guys, I stand corrected on the topic of DE and its toxicity

By: Vote For David

Vote For David — Wed, 25 Feb 2009 15:01:16 +0000

DE is pretty innocuous when it’s still riding in your tank’s (or rifle’s?) magazine. The nasty bit comes after it has turned the inside of an enemy APC to burned crispies . . . then you have slightly radioactive, toxic dust left from the round you shot them with. It’s one more thing to worry about (a little) when you are checking a burned out hulk for anything (or anyone) useful in the field

By: Nomen Nescio

Nomen Nescio — Wed, 25 Feb 2009 04:01:42 +0000

i’m an idiot who shouldn’t be posting so late at night. in addition to forgetting to close that link (i’d meant it to cover only two words…), i went and talked about fission products when i meant to talk about decay products. uranium (even depleted uranium) will spontaneously fission, too, but absent a nuclear reactor that’s such a rare event as to not much matter.

By: Nomen Nescio

Nomen Nescio — Wed, 25 Feb 2009 03:49:37 +0000

Carrying DE rounds around would likely be a health hazard to the soldier using them. not unless you suck on them like lollipops. or throw one in the campfire and inhale the smoke. depleted uranium metal really isn't all that radioactive --- the half-life is in the billions of years. the fission products are also radioactive, but not much more dangerous than uranium itself for several steps of decay; things don't get iffy until you hit radon, which is a gas, and so would be trapped in the metal matrix i'd wager. in fact, depleted uranium has been used as radiation shielding to protect against more vigorous radiators. works about as well as lead at that. has similar backdraws as lead too --- they're both toxic heavy metals, and you don't want to ingest either one.

By: EmptorMaven

EmptorMaven — Wed, 25 Feb 2009 00:43:51 +0000

I don’t know about this example, but rifled sabots are typically a soft material that will not wear on the gun’s bore. Besides, this gun must be a smoothbore since the flechette is not designed to spin. (Which would also explain why the flechette load wouldn’t work in a regular .50BMG rifle.)

Regarding the depleted uranium: It’s no more hazardous to touch than lead. What little radiation it does emit is of a very low energy. A marble floor or granite countertop could pose a greater radiological hazard. Granted, like most other heavy metals it is toxic. You don’t want to breath it or swallow it. Also, at high temperatures (like those created when a supersonic projectile hits a hard target) DU becomes “pyrophoric,” which means it will burn, releasing even more energy at the target.

By: Steve

Steve — Tue, 24 Feb 2009 23:14:17 +0000

I agree with jdun1911

By: jdun1911

jdun1911 — Tue, 24 Feb 2009 23:00:41 +0000

It will destroy any rifling in a matter of a few shots at the speed that the Flechette leaves the bore.

The fins is more then enough to stabilize the Flechette. The M829A1 is able to gets hit at over one mile.

By: Steve

Steve — Tue, 24 Feb 2009 21:17:01 +0000

Tony, lol. Seriously through: would you be happy to carry about radioactive decaying uranium in a pouch on your body? One thing in an aircraft, tank or ship (?) magazine, but another thing on the body. That is asking for trouble.

Also the chemical produced when DE corrodes can spontaneously combust at room temperature!

By: Woody

Woody — Tue, 24 Feb 2009 19:17:33 +0000

My friend and I were thinking the same thing Phil, twisted stabilizer fins would give the projectile better accuracy but it would slow it down. I don’t know whether it would slow it down to the point where range would be hindered but I bet it would (see murphy’s law: no good deed goes unpunished). Imagine arching the round, if the moa were tighter then you could reach further but again I have no idea what the specs would be. I’m sure they thought about twisting the fins but maybe you can’t effect a spin at speeds approaching mach4, maybe it would time travel, maybe they didn’t actually think of it, who knows? We never will and that makes me sad.

By: Daniel E. Watters

Daniel E. Watters — Tue, 24 Feb 2009 16:58:46 +0000

As for the fins, a former TRW engineer John R. Sellars has written that they did experiment with a slight fin angle. The original fin angle was 1 degree. This was found to add too much drag, adversely effecting the range of the fléchette. Sellars thought that they might be spinning so fast that they were bending the shaft in flight. Later efforts used a 0.5 degree cant. According to Sellars, 20,000 of the .50 BMG DU fléchette round were made.

FWIW: The prototype HIVAP rounds used steel fléchette. This was probably due to the weapon being a proof of concept model. DU fléchette are a bit much for function testing. You hardly want to contaminate the factory test range, and at ~30,000 rpm, it would get pretty expensive in short order.

Around the same time, AAI worked on DU fléchette in 7.62mm NATO. The latter had the unfortunate designation DUDS: Depleted Uranium Discarding Sabot.

I really need to add these to my article on SPIW and fléchette over at The Gun Zone.

http://www.thegunzone.com/spiw.html

By: Tony

Tony — Tue, 24 Feb 2009 16:51:09 +0000

“…and health concerns of depleted uranium.”

Oh please, not you too? The amount of hysteria these days over just about everything is quite depressing. I had higher hopes for such an intelligent blog as this.

By: Phil

Phil — Tue, 24 Feb 2009 11:30:03 +0000

Is it just me, or should there be some twist on the dart stabilizers? Seems like that would give it more range and accuracy.