7
$\begingroup$

I was surprised to read in this recent WSJ article about a black powder shortage:

Today, [black powder] is a specialty commodity with few commercial applications—mostly for rocket hobbyists—but it’s still used in more than 300 munitions, from cruise missiles, to bullets for M16 rifles, to the vital 155mm shells. In each case, a small amount of black powder is used to detonate a more powerful explosive packed in the same bullet or missile. A 155mm shell for a howitzer, for example, will use half an ounce of black powder, lodged next to 26 pounds of a more powerful explosive.

That's describing black powder being used as a detonator/primary explosive, which I had always understood it could not do because it is strictly a "low explosive" meaning it can't develop a supersonic shockwave (VoD). I have never seen black powder listed as a primary explosive. So is the article mistaken about its use in modern military explosives? Or does black powder serve some purpose other than detonation in those munitions?

Improve this question
$\endgroup$
3
  • 1
    $\begingroup$ Explosive booster? $\endgroup$
    – Mithoron
    Commented May 1, 2023 at 21:04
  • $\begingroup$ @Mithoron I've never heard of it used in that capacity either. That wikipedia article lists all the boosters I've heard of and does not mention black powder.. $\endgroup$
    – Lysander
    Commented May 2, 2023 at 0:00
  • 3
    $\begingroup$ It is pretty easy to assume the WSJ used the wrong terminology. It seems to confuse the nature of the propellant with the nature of the detonator, for example. Propellants are usually guncotton-based and this has nothing to do with the initiator of the explosion for shells containing explosives designed to blow up on arrival. Bullets, for example, don't have explosives designed to detonate on arrival, shells sometimes do. The WSj is confused on this. $\endgroup$
    – matt_black
    Commented May 2, 2023 at 9:52

1 Answer 1

Reset to default
1
$\begingroup$

I think black powder is used as a combustion initiator, to quickly raise temperature and pressure to the point where the main smokeless powder charge burns efficiently. BP is not pressure sensitive for its burn rate where nitrocellulose based propellants are very sensitive, burning faster at higher pressures. BP is a propellant, 'low explosive' with a relatively constant burn rate dependent on surface area. It is not a primary or secondary explosive; it does not detonate by shock propagation. I remember seeing that naval guns have a small pouch of black powder attached to the back of the smokeless powder bags. It would seem that 155mm artillery shells are similar.

Improve this answer
$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.