[LMB] Talking of Rocket Ship Galileo OT:

[Mark Allums]

Mark Allums wrote:
> B. Ross Ashley wrote:
>>> Let me rephrase that: rifles and pistols that were purchased
>>> at the local hardware store shortly before Our Heroes took off,
>>> with ammo ditto.
>> Mark Allums is correct, in his other reply to your original post, 
> Marna; gunpowder contains its own oxidiser, and needs no atmospheric
> oxygen to combust itself. (Guncotton, or nitrocellulose, "smokeless
> powder", as in modern cartridges, is another kind of explosive, on the
> order of nitroglycerin ... a specific sort of shock will set it off.)
> 
> Yes, and I should point out that modern smokeless powder is not really
> a "gunpowder"  A gun may contain a substance that doesn't
> necessarily "burn"  High explosives merely turn from solid or liquid to 
> a gas really, really fast.  There can be flame, because it's a very 
> rapid release of energy.

I don't know if this is worth the list traffic, but:  I meant to say 
"should have pointed out".



You guys are good to keep an eye on me.  I often get impatient, and fire 
off posts that contain goofs like this.  I know what I am trying to say, 
but I have trouble putting it into words.  It used to be that I only had 
this problem in speaking.  In writing, I did fine.  The problem has 
progressed to writing now.  I end up leaving out important details.

Heinlein's heroes were undoubted using smokeless powder, it's been 
around for a very long time.  :)

Marna, if it becomes a serious problem you need to solve, there are 
plenty of places to turn for very good explanations of this.  But:

1. load cartridge
2. cock the weapon
3. pull trigger
4. firing pin strikes primer
5. primer[1] explodes
6. explosion triggers reaction in "powder"[2]
7. powder produces rapidly expanding gas
8. pressure of gas propels bullet down barrel
9. rifling of barrel causes bullet to spin, like
    a well-thrown football, stabilizing bullet in flight


--MArk Allums

[1] primer has two meanings,
     a. little can coated with chemical inside
     b. chemical itself
[2] Rifle "powder" is actually long, little sticks, which,
     when lit on fire in the open air, burn surprisingly slowly.
     (I've done it.)