/k/ - Weapons

By double posting.

>>549834

So a M4 that fires ceaseless ammo?

>will fuck up

already happened at design brief level.

They took the current weight distribution of the modern soldier and decided it would be good to take weight away in areas that are supported by the legs and spine, and add weight to areas that also must be supported by the arms and shoulders. they saved some weight yes, but they also made several pounds of a soldiers gear fundamentally less energy efficient to carry. They also went ahead and found a way to make a gun with a standard trigger configuration even more problematic to clear a jam than a bullpup, all for the sake of plastic bullets. The entire system could be done better if they just used steel cased ammo with their fancy new compressed powder in a regular old rife, they still save weight but they also wouldn't be adding any.

>>549834

Meanwhile in Russia all the new contracts have (finally) been attributed.

It's AK-12 for the infantry, AEK 971M (A-545) for spec ops, RPK-16 for LMG, and it does seem that PKP for GPMG with backpack systems are a real thing as they're more than the couple of prototypes that keep showing up in photos, but it would seem they're issued in two config "light" PKP (regular) and "support fire version" with backpack and heavy optics, possibly tripods.

Interestingly the RPK-16 comes with a 96rds drum and no recoil compensation, instead it gets a quick barrel takedown system. I'm guessing it will still use 1 "assault" drum and the old 45 rds mags for reloads. It's extremely interesting because the RPK had virtually disappeared from Russian forces.

There was a belt fed 5.45 in competition (Tokar-2) but belt fed/different weapon at that level was deemed more of a hassle than anything (as usual).

>>549850

Aren't they issuing that new RPK with a short barrel as well? I have a feeling they've taken lots of notes on what happened on the other side of the border, those rebels loved the shit out of their RPKs.

>>549853

>that new RPK with a short barrel as well

They're issued with both AFAICT, a short one and a long one.

>>549859

That is what I was getting at.

>>549834

Why can't they just make these cases with an extractor groove?

Mechanically the chamber "swings" to extract the spent or malfunctioned case and basically a dowel rod connected to the op rod pushes the round backward.

>>549861

Because the reason for the floating chamber is that the polymer case can't handle the pressures and needs to be fully supported rather than brass or steel expanding to full the chamber then contracting to allow extraction.

In other words all you would do is tear caseheads and cause a cluster fuck of a malfunction every 3 shots

>>549861

>>549864

Not only that, but the swinging chamber keeps the chamber away from the heat being generated at the barrel, which helps mitigate overheating and cook-off concerns.

As for the OP, nice to see the LSAT program going somewhere, I've been hearing that its adoption was "imminent" for three years now.

>>549864

I'm well aware of why a floating chamber is needed, I'm saying that it "swings".

it doesn't slide, it's literally on a hinge that can be broken easily if there's gunk built up in the gun that messes with the timings of the mechanism itself.

It's right there at 1:23 in this video.

They should have also just went with a brass or steel or even aluminum case.

>>549870

>heat in the chamber

Heat in the barrel is generated from the gas and the friction of the round going down the bore, most of the heat in the chamber is pulled out with a metallic case.

You get a hot case but a "cool" chamber.

>>549871

>Heat in the barrel is generated from the gas and the friction of the round going down the bore, most of the heat in the chamber is pulled out with a metallic case.

But with a polymer case you don't have that, because it doesn't conduct heat nearly as well. Hence the need for the swinging-arm chamber, in addition to the case-tearing concerns brought up.

>>549874

see above, they should have went with a metallic case for this, maybe aluminium.

The main problem I see with these caseless designs is that they keep thinking in terms of a "case without a case" instead of truly caseless.

Something like this for example.

>>549876

reliably metering out powder per shot to make a bullet firing engine would be very awkward, it would also mean that you cant use the fancy new powders they designed in the LSAT program. Im not sure it would resolve the issue of residues either since not everything left behind after caseless ammo is fired is binding agent. I think the best way to do it would be to create a manufacturing process which can form a solid structure propellant pelet without the need for binding agent. easier said than done though, which may sum up the entire caseless system.

>>549861

Polymers are weaker than metals and maybe be ripped by extractor. Making base from teh metal is heavy (base of teh case with the grove is like 40-50% of its weight).

Anyway it should be noted that CTA started as caseless project. With caseless ammo they had no choice of configuration. Only telescopic round and push through extraction. Polymer case was backup solution over caseless ammo.

>>549883

He's pulled this off with a bolt action rifle as well and it's pretty consistent.

It doesn't load the powder itself, he does it with a reloading measure but I'm pretty sure it can be done.

He can also double load his handgun as well.

You have to remember, he designed that handgun in his workshop and only made it once. Pretty sure if he refined the design it would be pretty consistent.

> I think the best way to do it would be to create a manufacturing process which can form a solid structure propellant pellet without the need for binding agent.

they might have to go with some type of polymer explosive for that, using regular smokeless will prove problematic.

If they do go for a polymer explosive however, they can reduce the mass of the cartridges by using less propellant rather than playing around with different materials of the casings.

>>549871

It doesn't swing on a hinge, it rotates around a central shaft. It's more like a revolver cylinder then anything. The gap between the breech and barrel would be the biggest problem really.

>>549874

Polymer not conducting heat as well isn't a problem as most of the heat is inside the case after firing. The case has to then transfer the heat to the chamber walls.. Also this system wouldn't solve heat problems as there is still only one chamber.

>>549938

Not sure that the ACR action is compatible with LSAT ammo as is, the polymer cases have to be fed perfectly flat otherwise the bullet shifts inside and causes reliability issues. i imagine that wasn't an issue when a flechette was running down the full length of the case. from info i believe you gave to me they already have a really stupid m4 which is the same thing but 9.5lbs

>>549961

I'm not the one who made it, and you are free to make a better one.

>>549960

why does the patent image show a casing entering the chamber at an angle? it even shows a feed ramp above 6 in figure 2.

>>549962

I wasn't talking about the quality of the image.

>>549968

It looks like 8chan has a NEXT LEVEL QUALITY again, and I can't post normally. I obviously didn't mean to put memearrows there.

>>550000

Calling it now, both weigh more than they are supposed to and we just end up with M16A4s and M4s until 2040.

>>550004

>we just end up with M16A4s and M4s until 2040.

>the replacement in 2040 will just be an upper receiver swap using whatever tech is available then

>>549871

How do they get a good seal between the chamber and barrel? Do they simply lose a huge amount of gas around the gap like with a revolver? That seems too dirty and velocity limiting to be the case.

>>550013

http://www.thefirearmblog.com/blog/2017/03/11/interview-kori-phillips-program-officer-lsat-ctsas-part-1-program-history-ammunition-technical-discussion/

https://archive.fo/7zfrg

http://www.thefirearmblog.com/blog/2017/03/18/interview-kori-phillips-program-officer-lsat-ctsas-part-2-ammunition-technical-discussion-contd/

https://archive.is/fy2Rk

http://www.thefirearmblog.com/blog/2017/03/25/interview-kori-phillips-program-officer-lsat-ctsas-part-3-development-6-5mm-ct/

https://archive.fo/h4v81

From part 2:

>TFB: You obviously have to have a separate chamber and a separate barrel unit. One thing that might be a negative is that on a revolver you have a gap there, where gas can escape. Do you have that problem, or have you found a solution to that?

>KP: For case telescoped, the front of the cartridge actually seals the breech, and the plastic flows into the empty space. It’s sort of a balancing act to let the cartridge expand and flow, but not so much that you can’t get the case out of there. It obturates the chamber just like it would with a brass case.

>>549968

looking at ACR round. How did they load them? inserting forward plug from forward to abck would compress air inside case.