.45mm machine gun?
Jyme
http://www.wsmv.com/news/21532281/detail.html
it states: ". . . agents also found a 5.56mm caliber rifle and a .45mm
caliber machine gun . . . ."
A machine gun with bullets smaller than a pin? (The only stick-pin I
could find measures .49mm in diameter.)
While the idea is intriguing (the bullet can probably pass through the
weave of a bulletproof vest), it raises a variety of questions.
How fast does the bullet have to travel to pack the same punch as a
standard 9mm slug? (Compare mass times velocity, but the mass cannot
be calculated with knowing the length of the .45mm bullet, and I
hesitate to speculate without knowing relevant bullet dia/length
ratios.)
Assuming the velocity would have to be very high, what streamlining is
used to ensure that air friction doesn't melt the bullet in flight?
How many rounds a minute can the weapon fire? (Reduced bullet weight
means less recoil and other strains on the mechanism, but is there an
upper performance limit?)
How accurate is such a small projectile?
I'm all for kinder, gentler wars, but shooting the enemy with pins
seems, to me, to be a bit of underkill.
John Park
You forgot to ask if the projectile could be spun well enough to avoid
tumbling, or whether it would need fins.
--John Park
WaltBJ
> In an Associated Press articlehttp://www.wsmv.com/news/21532281/detail.html
> it states: ". . . agents also found a 5.56mm caliber rifle and a .45mm
> caliber machine gun . . . ."
Most reporters haven't a clue about firearms.
I'll go further and opine that the piece in question is really a
submachine gun.
Walt BJ
Mike Ash
Jyme <jym...@dialup4less.com> wrote:
> In an Associated Press article
> http://www.wsmv.com/news/21532281/detail.html
> it states: ". . . agents also found a 5.56mm caliber rifle and a .45mm
> caliber machine gun . . . ."
>
> A machine gun with bullets smaller than a pin? (The only stick-pin I
> could find measures .49mm in diameter.)
>
> While the idea is intriguing (the bullet can probably pass through the
> weave of a bulletproof vest), it raises a variety of questions.
>
> How fast does the bullet have to travel to pack the same punch as a
> standard 9mm slug? (Compare mass times velocity, but the mass cannot
> be calculated with knowing the length of the .45mm bullet, and I
> hesitate to speculate without knowing relevant bullet dia/length
> ratios.)
If you assume that it's the same shape as the 9mm slug, you don't need
to know what that shape is. Your hypothetical bullet is 1/20th the
linear dimensions, and thus 1/8000th the volume and, if the same
materials, mass. To have the same kinetic energy, it would need to go 90
times faster.
An AK-47 has a muzzle velocity of 710m/s. If we assume it arrives at the
target with similar energy, this fellow would need to arrive at 64km/s.
> Assuming the velocity would have to be very high, what streamlining is
> used to ensure that air friction doesn't melt the bullet in flight?
Drag is proportional to frontal area, but mass is proportional to
volume, so with the same shape, your drag-to-mass ratio (or, your
deceleration) is 20 times higher. Heating will be proportionately higher
as well, I think. However, that's 20 times higher *at the same
velocity*. Drag is also proportional to the square of the speed, so you
get 8000 times greater drag if you start out at 64km/s. Which in turn
means you need to start it out much faster yet so it gets to the target
at a good speed, but that means even more heating, etc. In short, I
don't think you can make this thing go any kind of distance before it
completely vaporizes.
--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon
Greg Goss
With that much friction to mass , will a "needler" projectile have any
impact once it's a few feet from the gun? NATO snipers in Afghanistan
make shots at huge distances. Do they use a heavier bullet to
maintain impact after punching through a long distance of air?
Angular momentum depends on radius, doesn't it? Can you maintain the
tumble-resisting spin for any distance?
--
apart from one noisy guy up in Canada, no-one wants
a three-cylinder tissue box on bicycle tires.
Carey
J.J. O'Shea
(in article <d0i9f5pjdn6l9bhsk...@4ax.com>):
> In an Associated Press article
> http://www.wsmv.com/news/21532281/detail.html
> it states: ". . . agents also found a 5.56mm caliber rifle and a .45mm
> caliber machine gun . . . ."
They almost certainly mean a .45 _inch_ _submachine gun_. Examples of such
would include the classic Thompson gun, and the M3 'grease gun' issued to
American forces during WWII. Exactly why our hero would waste his time with
literal museum pieces instead of something more modern, with a better cyclic
rate and larger ammunition capacity, like say a P90 (the guns hauled around
in the later seasons of Stargate SG-1) is probably best explained by whatever
pathology is behind his other behavior.
This kind of grossly inaccurate reporting does not surprise me. I once read a
novel where the author showed the exact depth of his (lack of) knowledge
about firearms when he insisted, repeatedly, that the Browning M2 heavy
machine gun had a caliber of 50mm, or around 2 inches, instead of its actual
.50 inch (12.7mm) caliber. Apparently he vaguely understood that the standard
German antitank weapon at the time specified was 50mm in caliber, so he had
his heroes engage heavy armored vehicles and use Ma Deuce guns to destroy
them. Yes, the .50 BMG Armor-Piercing-Ball round is a very powerful bullet,
and yes it was directly descended from a German 13mm anti-tank round... from
the _First_ World War. WWI tanks were slightly less robust than WWII tanks,
so _no_, .50 BMG APB will NOT penetrate the frontal and turret armor on a
Pzkw Mark IV. If you got close enough and aimed for the side or the rear or
the top deck you'd have a chance. A fairly good chance if you aimed for the
rear or the top deck, actually; a good number of Mark III and Mark IV tanks
were destroyed by .50 BMG from the air. Aim for the bow plate or the turret
and all you'll do is annoy the tank's crew until they crank the turret around
and load HE and blow you away.
--
email to oshea dot j dot j at gmail dot com.
John Park
To be fair (or pedantic), the speed of the aircraft might be enough to double
the KE of the bullets.
--John Park
Tom McDonald
One of the tricks of Allied tank killers was to aim at the ground
in front or behind the tank, and let the ricochets rip through
the thin floor.
>> and all you'll do is annoy the tank's crew until they crank the turret around
>> and load HE and blow you away.
>>
>
>
>
>
>
>
>>
>>
>> --
>> email to oshea dot j dot j at gmail dot com.
>>
>
>
--
Tom
When Tyrants tremble, sick with fear,
And hear their death-knell ringing;
When friends rejoice, both far and near,
How can I keep from singing.
Jyme
>In article <d0i9f5pjdn6l9bhsk...@4ax.com>,
> Jyme <jym...@dialup4less.com> wrote:
>
>> In an Associated Press article
>> http://www.wsmv.com/news/21532281/detail.html
>> it states: ". . . agents also found a 5.56mm caliber rifle and a .45mm
>> caliber machine gun . . . ."
>
> In short, I
>don't think you can make this thing go any kind of distance before it
>completely vaporizes.
So instead of hitting them with a bullet, you're actually spraying
them with superheated ions?
Jyme
wrote:
>Jyme (jym...@dialup4less.com) writes:
>> In an Associated Press article
>> http://www.wsmv.com/news/21532281/detail.html
>> it states: ". . . agents also found a 5.56mm caliber rifle and a .45mm
>> caliber machine gun . . . ."
>>
>> A machine gun with bullets smaller than a pin? (The only stick-pin I
>> could find measures .49mm in diameter.)
>
>tumbling, or whether it would need fins.
>
projectile less than 1/50 of an inch in diameter. :)
Steve Hix
Jyme <jym...@dialup4less.com> wrote:
Sabots. Teeny sabots.
Erik Max Francis
Yup, you nailed it. Wrong twice.
--
Erik Max Francis && m...@alcyone.com && http://www.alcyone.com/max/
San Jose, CA, USA && 37 18 N 121 57 W && AIM/Y!M/Skype erikmaxfrancis
The cost of freedom is always high -- and Americans have always paid
it. -- John F. Kennedy