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Posted: Wed Aug 08, 2007 9:07 pm
by goathunter
DYI: the m829 weighs in at 41lbs and it fits the 120mm. main gun on an Abram.

http://en.wikipedia.org/wiki/M829

I can pretty much guarantee that if you were able to reproduce such an item to be fired out of a spudgun the feds would be on your door step. :D

BTW: Fun little gun you got up in the pics.But why didn't the dowel shatter?Is it coated or something?

Posted: Wed Aug 08, 2007 10:07 pm
by jackssmirkingrevenge
goathunter wrote:But why didn't the dowel shatter?Is it coated or something?
Path of least resistance I'm guessing, the materials it went through were all wood or similar.

Posted: Thu Aug 09, 2007 12:01 pm
by joannaardway
jackssmirkingrevenge wrote:let's take for example the US Army's, solution to the problem, the M829 kinetic energy penetrator - that leaves the barrel at over 5 times the speed of sound with a whopping 4,391,500 ft/lbs :shock:
Pittance.
The Maxwell Labs' Railgun throws a 1.6kg (3.5 lb) projectile at 3300m/s (10830 fps, roughly Mach 10), for 6,429,520 ft lbs of energy - at a decent (for a railgun) 27% efficency.
Of course, it's not pratical as an anti-tank weapon yet, but it shows what the future could be like.

Those DU rounds are pretty hefty. Having been part of the Army cadets (Royal Artillery), I've been shown the typical anti-tank rounds, including a APFSDS DU round (not sure what exact variant).
The thing that strikes you about all the (non-explosive) rounds is just how much they all weigh. You look at the tungsten steel one, think "That can't be that heavy", then when it's passed to you, you nearly drop the thing - because it weighs more than twice what you think it does.

@goathunter: The DU round wasn't anywhere near 41 lbs in weight. As a rough guess, it was 10-12lbs tops.
Are you sure that 41 lb number doesn't include the propellant charge?

Posted: Thu Aug 09, 2007 12:10 pm
by jackssmirkingrevenge
According to Fr. Frog, the actual projectile weighs in at around 10 lbs.

Rail guns are a long way from being practical but IIRC the US Navy are evaluating them as a ship-borne weapon that would offer a cheaper alternative to cruise missiles for certain applications - have a look here for further info.

Posted: Thu Aug 09, 2007 12:29 pm
by joannaardway
That weight sounds about right.

How soon the armed forces will be able to use a railgun that doesn't require a full service after each shot is going to be an interesting one to watch.
To me, my view is that for the immediate future, the railgun and it's cousins, the coilgun and gauss gun are mostly in the realm of the hobbist and computer gamers, but obviously the practicality issues will eventually be sorted to make it militarily viable.

Posted: Thu Aug 09, 2007 12:37 pm
by Gepard
I wonder which will see active service first - rail/coil/gauss gun or lasers.....

Michael

Posted: Thu Aug 09, 2007 12:50 pm
by spud yeti
I'd probably have to go for rail guns

(I edited all the rest out, because it was stupid, sorry folks)

Posted: Thu Aug 09, 2007 12:54 pm
by joannaardway
Gepard wrote:I wonder which will see active service first - rail/coil/gauss gun or lasers.
I'd lean towards the kinetic energy based ones. Lasers have several disavantages.

Posted: Thu Aug 09, 2007 1:06 pm
by DYI
Due to the massive amount of power required, and the relatively low amount of destruction, lasers are only really practical for shooting down missiles from long range, as there are far quicker and more economical alternatives for neutralizing tanks/infantry/ships.

Because of this, I think that it will be a long time before lasers become a viable anti-infantry/ anti-armor weapon.

Posted: Thu Aug 09, 2007 1:09 pm
by Gepard
I was thinking about solely anti personnel and armour warfare I was thinking more generally.

IIRC there is already a land vehicle based laser weapons system that's being tested at the moment....

Not sure on the status of the plane based one though.....

Michael

Posted: Thu Aug 09, 2007 1:39 pm
by jackssmirkingrevenge
Gepard wrote:IIRC there is already a land vehicle based laser weapons system that's being tested at the moment...
Land based laser shooting down mortar rounds, and here's the anti-missile airborne laser.

It's interesting to see how laser armour will develop, probably along the lines of heat dissipating ceramic that is used to counter shaped charge warheads.

I'm with kinetic energy projectiles personally :)

Posted: Thu Aug 09, 2007 1:46 pm
by DYI
Yes, it is rather difficult to build an armored vehicle that can stop something moving at Mach 10 with ~6 000 000 ft/lbs of energy while still being able to move.

Posted: Thu Aug 09, 2007 1:50 pm
by jackssmirkingrevenge
DYI wrote:Yes, it is rather difficult to build an armored vehicle that can stop something moving at Mach 10 with ~6 000 000 ft/lbs of energy while still being able to move.
It's hard enough to stop a broomstick eh :wink:

Posted: Thu Aug 09, 2007 1:56 pm
by DYI
Now we just have to get the broomstick going at Mach 10... :D

Posted: Thu Aug 09, 2007 4:48 pm
by goathunter
joannaardway-"@goathunter: The DU round wasn't anywhere near 41 lbs in weight. As a rough guess, it was 10-12lbs tops.
Are you sure that 41 lb number doesn't include the propellant charge?"

I was talking total weight, not just the dart itself.You are correct.I should have been more specific.

Speaking of tungsten steel:
I know its expensive but has anyone tried shooting tungsten rods like welders use?I keep on trying to get my dad to let me borrow one of the rods for "experimental" use, but he won't let me(I think I shouldn't have told him it'd be exiting my spudgun's barrel).




Jack,You left out the pain "laser" that is mounted on a humvee for crowd control. Nothing as cool as a long range microwave oven to cook frozen burritos/occasional mobs :D
But I'm with you on kinetic projectiles.Even if a vehicle does have armor enough to stop a round like the one mention, the vehicle is quickly unable to be airlifted and mass produced cheaply.That is at least with the current military norm. :wink: [/quote]