Why not Tungsten match rounds for 70% greater ballistic coefficient?

[TXAZ]

I understand it is difficult to machine, but with a 70% greater density than Lead, and assuming you could machine the exact same size match sized ammo, why wouldn't competition shooters go for the much higher Ballistic Coefficient of a tungsten round when cost for some of the large bore match ammo can be $5-15 per round for .50 BMG for instance.

I'm sure there's a reason for it but I couldn't find it.

 

[Metal god]

That would be a "AP" round , not to mention the cost those would be . I know my tungsten darts cost a couple bills . There might be a very small market for something like that though .

 

[SSA]

Instead of a 750 gr 50 cal bullet you'd have a 1250 gr 50 cal bullet. What velocity could you get with that?
Don't know how much difference there would be in BC.

 

[Jimro]

Tungsten carbide penetrators are available in the military market. They aren't exactly totally awesome sauce in terms of terminal effects. The Raufoss M211 is a good round, but honestly the penetrator there is a bit of an afterthought, more designed to kill engine blocks than anything else, which is something that normal 50 cal ball can do quite nicely.

Remember Energy = 1/2 Mass times Velocity squared, so increasing mass is less effective at energy generation than increasing velocity. Force = Mass times Acceleration, so a given mass will have more force for any given acceleration (such as impact which is a negative acceleration of velocity). However, tungsten doesn't deform well, it either holds together and makes a nice hole, or if it hits something hard enough will shatter.

So this is the reason that no one makes pure tungsten bullets, or even uses tungsten penetrators in the bulk of their 50 caliber bullets, and saves the Tungsten for the Armor Penetrating Fin Stabilized Discarding Sabot main tank gun rounds.

Here's a NAMMO brochure with good pics: http://www.dtic.mil/ndia/2015smallarms/17379_Erninge.pdf

Jimro

 

[brasscollector]

The melting point of tungsten would make it difficult to deal with. At roughly 6200 degrees fahrenheit it would melt nearly any mould you'd be pouring it into (short of ceramic). Not sure if forging would work or just beat up the tooling either. Also, as others have pointed out, trading the density for velocity is a losing proposition.

 

[TXAZ]

I was sure there was a reason, thanks gentlemen!

 

[jmorris]

You could get tungsten rod and shape them into bullets. Would be pretty hard on the rifling though.

In any case weight is not the only factor in calculating BC shape is important (why bullets of the same weight have different BC's). What would your example be to reach a 70% gain in BC?

 

[Pond James Pond]

It's also absurdly hard, I believe. BHN of bazillions

So I imagine that would slash the life-span of the rifling unless a copper jacket were made thick enough to absorb the rifling cut entirely. Even then, the bore would surely suffer far heavier wear.

 

[F. Guffey]

why wouldn't competition shooters go for the much higher Ballistic Coefficient of a tungsten round

I do not know; but, I find nothing exciting about chambering a round in a rifle with a projectile that is too hard to imprint to the rifling. I can only imagine the amount of pressure required to force the projectile down the bore.

There is always insulators like a sabot.

http://www.sabotreloadingpro.com/

F. Guffey

 

[mapsjanhere]

While tungsten is impractical, if you can afford it gold would make you a decent bullet with 50% higher sectional density. So you probably want to use your own gun range with a bullet recovery backdrop, at $250 per 100 gr .22 the price is steep, even for a benchrester.

 

[briandg]

Two points, for the first part, it might invoke intervention from atf. Tungsten handgun bullets of any sort, if I understand, are illegal for use by civilians, as well as several other other types.

Now, for the important part. adding tungsten to any bullet and retaining the same weight Will shred your bc, not improve it. Consider this. Take a 158 gran semi wadcutter and consider how scrappy the bc is. Then consider a 150 grain spitzer in .308. Enormously increased bc. Then think about a good vld match/ long range bullet. Maybe solid copper so it can be lighter, and stretched out even longer. Or put in a lightweight polymer tip and a lightweight hollow cavity under the tip.

Sectional density only considers the weight and diameter. No matter how it is shaped, a 150 grain.308 bullet would have the same sd. The bc is dependent on both the bc and shape. Stretch it out, make it more aerodynamic, even change the material so that it's even more streamlined, and yo will increase that bc even more.

Go to Sierra website and study the information on .308 bullets, for example, and the bc numbers.

The most common means of measurement, if I'm not mistaken, is to fire a bullet, and measure velocity at muzzle and a number of distances. By finding the velocity charges, the mathematically work backwards to get bc.

So no, adding tungsten, or or any denser material will do nothing but make your bullet a bit stubbies and lower your bc.

 

[SSA]

Speer made a solid hunting bullet with a tungsten alloy core 20 years ago. Barnes used to make a copper bullet with a tungsten alloy insert.
The military bullets are jacketed tungsten carbide. Or at least some of them are, or were. Denser than lead, not as dense as tungsten.

 

[RC20]

Per above, you don't' have to have all tungsten, just a core and right location and balance and build a bullet structure around it.

They put copper over lead, more complicated obviously but not undoable.

On the other hand, it sure would cost.

Key is it does not have to have anything to do with penetration (AP).

Me, I am waiting for the depleted uranium round!

 

[T. O'Heir]

Tungsten is too light, expensive and brittle. Hard to work too. Isn't the same thing as tungsten carbide either.
Military bullets are jacketed with copper or mild steel. WC is way too hard for bullet jackets.

 

[Pond James Pond]

Tungsten is too light

Light?!

It has a density of 19.25gr per cm3, to lead's 11.34gr!

 

[RC20]

Tungsten is too light, expensive and brittle. Hard to work too. Isn't the same thing as tungsten carbide either.
Military bullets are jacketed with copper or mild steel. WC is way too hard for bullet jackets.

Light? Hmmm

And it does not have to be jacketed or anything.

You make a core of tungsten that replaced the lead (less), it just has to balance the bullet right for the job.

I am not saying its remotely worth it but it can be done.

And I still thing depleted uranium is the way to go.

For game use there is no residue and you can scatter that previously nasty stuff around and let it go back to nature.

 

[Jimro]

Tungsten and DU are nasty things to work with, and have no real usefulness outside of destroying armored vehicles. Certainly the copper and lead hunting bullets we have available cover down on all our hunting needs so far, so until something new comes along that is armor plated, no need for tungsten.

As far as an increase in BC goes, sectional density has to do with the frontal area of the bullet and the total mass of the bullet. You'll get a higher BC from a less dense bullet over a more dense bullet for the same mass, for example going from the Copper/Steel/Lead M855 to the Copper/Steel M855A1 we gained a little BC because even though the sectional density was the same, the less dense M855A1 is longer with a better boat tail and more consistent bullet base.

The time to increase the projectile mass is when you can't reasonably increase the velocity any more, such as for 20mm and larger Cannons and Tank rounds. The effect of putting tungsten penetrators in small arms bullets is really context specific. Small arms are generally for shooting at people, so an armor piercing 5.56 bullet isn't going to give you any better terminal performance than an Mk318 bullet, through normal barriers (car windshields, doors, etc).

As far as any potential increases in accuracy, the most accurate bullets are match bullets with a reverse drawn jacket and uniform lead core, this is mostly because these bullets are the easiest to make uniform for imbalance and for uniformity of external dimensions. The old Garand shooters did like AP ammo for matches because the 160 some odd grain bullets did have a better BC than the 150gr M2 ball ammo, but some AP ammo was constructed with poor bullet imbalance and so you'll find a lot of differing opinions on the matter.

So generally, less dense and longer is better for ballistics because you can get a higher BC bullet at a higher velocity (within the realm of Copper, Steel, and Lead).

Jimro

 

[briandg]

Yes, Speer did make a tungsten cored rifle bulle5, the grand slam safari. The thing had a big, heavy tungsten core that was probably sintered to shape, and in sure that it wasn't swaged like typical lead. That extra heavy jacket appeared to essentially be folded over the base, so the somewhat brittle core wasn't stressed by intense pressure of swaying.

They were about 20%shorter than lead solids, and allowed a few more grains of powder with the same goal.

People didn't buy them. The monolithic bronze bullets won the market. The bronze solids were turned and needed no carting around with a core. Much cheaper to make, probably.

 

[noylj]

Why not gold or DU?

 

[RC20]

DU has been brought up in two posts above by yours truly as well as answered by Jimro.

I like the gold idea though. For billionaires and jet setting exclusive hunting camp (luxury inn) Supreme Court Justices.