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armour piercing ammunition   Ammunition <20mm

Started 28-Dec by graylion; 3013 views.
Red7272

From: Red7272

29-Dec

graylion said:

I am going for something that can be carried in a thigh holster - like the Keltec gun we are discussing in the other thread.  Where I am at is this bullet: http://www.geoffrey-kolbe.com/cgi-bin/drag_working.cgi?unit_length=mm.&weight_unit=grains&bullet_name=GLS+PDW+II&re_calculate=yes&boundary_layer=L%2FT&diameter=6&length=28&nose=14&meplat=0&drive_band=6.15&base_diameter=&angle=7.1&boat_tail=5&secant_radius=6.6&weight=62.3&density=8.12 which with my cartridge gives me 1417 J aka 1198 ftlb at a V0 of 2755 ft/s. At 300 yds it retains 2031 ft/s at an energy of 651 ftlb. This is from a 10.5" barrel, using drive bands.  What concerns me is the muzzle pressure of 13.500 psi.

Oh god not again. 

graylion

From: graylion

29-Dec

The problem is that tungsten is a) highly toxic and b) not available in sufficient quantity.

renatohm

From: renatohm

29-Dec

And c) too expensive for all but some niche roles

ZailC

From: ZailC

29-Dec

Tungsten toxic? I don't think so. 

roguetechie

From: roguetechie

30-Dec

That'd definitely do it. Pointy fast and with a hard ass steel core will do what you want most reliably.

Increasing the diameter will make it worse not better.

In a pdw cartridge you're looking for a certain amount of force per mm squared at the point of impact.

Because of the wide variety of armors you potentially face this is the best generic answer.

Our dear friend has been doing some evaluation on notional super 5.7x28 loads and projectiles and it's very possible to make something that punches level 3 very handily.

That said, one thing to keep in mind too though is that m855a1 and m80a1 are designed specifically to be ESAPI safe. So there isn't a cookie cutter answer here.

In reply toRe: msg 24
graylion

From: graylion

30-Dec

ZailC said:

Tungsten toxic? I don't think so. 

"That delay proved fortuitous. For before production could begin, new studies disclosed that tungsten was at least as environmentally hazardous as lead and that it could leach into soil."

https://www.americanrifleman.org/articles/2014/5/28/the-m855a1-cartridge-a-long-time-coming/

"All tungsten compounds should be regarded as highly toxic. The metal dust presents a fire and explosion hazard."

https://www.lenntech.com/periodic/elements/w.htm#:~:text=Chronic%20health%20effects%3A%20This%20product,a%20fire%20and%20explosion%20hazard.

  • Edited 30 December 2020 1:37  by  graylion
graylion

From: graylion

30-Dec

roguetechie said:

Increasing the diameter will make it worse not better.

Yes, which is why I don't want to increase the diameter of the steel penetrator. Fundamentally I want a bullet that holds together when hitting a soft target and separates when hitting a hard one.

And yes, I believe VBR did this.

  • Edited 30 December 2020 2:24  by  graylion
mpopenker

From: mpopenker

30-Dec

graylion said:

For recoil control, I'd try balanced recoil

Sorry, friend, but you're on a wrong track

balanced recoil action helps to negate recoil impulses of the heavy bolt group; it has nothing to do with recoil impulse of the round itself, and for that you need a muzzle brake

also, balanced action adds weight, significant cost, and complexity in routine maintenance

Finally, it badly affects cyclic ROF - in assault rifles like AK-107 or AEK it increases ROF from typical 600-650 rpm to 900-1000 rpm, and in smaller subguns with balanced action ROF goes up through the roof with 1200+ rpm

I did quite  study on this subject, so sorry to disappoint you - it's an answer in need for a question, not vice versa

graylion

From: graylion

30-Dec

mpopenker said:

balanced recoil action helps to negate recoil impulses of the heavy bolt group; it has nothing to do with recoil impulse of the round itself, and for that you need a muzzle brake also, balanced action adds weight, significant cost, and complexity in routine maintenance Finally, it badly affects cyclic ROF - in assault rifles like AK-107 or AEK it increases ROF from typical 600-650 rpm to 900-1000 rpm, and in smaller subguns with balanced action ROF goes up through the roof with 1200+ rpm

That is disappointing, but thanks!

gatnerd

From: gatnerd

30-Dec

graylion said:

The problem is that tungsten is a) highly toxic and b) not available in sufficient quantity

The problem with steel is that it does not penetrate modern Level IV armor even at point blank ranges. And Level IV is now the basic default for hard armor. 

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