Idea: Tube-fed AR conversion. (pics added)

[Euphoria526]

HK and FNH are working on this. The primary prototype is their LMGs at the moment but when they get it right they'll expand to small arms. You can check out the LSAT program for more info. Basically they're using polymer cased telescoping ammo. The big hurdle here is heat. Brass serves as a heat sink, polymer not so much. With caseless this is a huge problem to the point of cookoff.

Top is caseless ammo, middle is brass 5.56 without projectiles, the bottom is the telescoping polymer ammo with projectiles. Weight savings is somewhere around 50% over brass.



-W

That's the first thing that I thought of for the polymer case idea. I agree about the heat issue, but because it's a smaller caliber than an LMG, wouldnt/ couldnt you use less /OR a different powder (I don't reload so I have no say) to flatten out problems with heat? What about using polymer blends with similar components more heat resistant? I'm new to all this I just like asking questions lol. I'm not really thinking about cost more just the idea of crazy possibilities. I swear I'm not as stupid as I sound lol v

OK, lets imagine the "normal" price of 223, around 30-40 cents a round. Think about how much of that caliber is produced, how many factories are kicking it out, and the quantities. Let's not forget how much of that XM855 is "rejected" or overruns of military ammo.

Now, think of this new caliber, specially made for honestly, a gun that will have little to no popularity outside of CA (and probably very limited within the state ).

So, low production, low demand, low factory support. Want to take a guess how much that ammo will cost when you figure in all of that?




If anything, I would look at just trying to produce 300blk with a flat point design. This would pretty much make it a reloaders only type of rifle though, but a specialty ammo producer would be able to still minimize cost with it.

I definately understand that the cost would outweigh demand, just throwing ideas out there to maybe spark someone else's imagination into prototype. It would be cool, but it would definate cost too much vi also agree it would be more useful for a more purposeful round. But it could also possible get adapted somewhere by some military I dunno, but it might have interest outside ca, but no reason because we're under the spyglass all the time compared to neighbor states.

[sharxbyte]

Thats why I suggested a "cap" of some sort to stick onto ammunition. I know that plastic tipped hollow points are available, but being able to add a semi cheap adhesive cap to the tip of a bullet would allow the use of standard ammunition instead of requiring a whole new caliber rework.

[zfields]

I think you would be seriously messing with the ballistics of the round by just sticking a cap on it.

[starsnuffer]

That's the first thing that I thought of for the polymer case idea. I agree about the heat issue, but because it's a smaller caliber than an LMG, wouldnt/ couldnt you use less /OR a different powder (I don't reload so I have no say) to flatten out problems with heat? What about using polymer blends with similar components more heat resistant? I'm new to all this I just like asking questions lol. I'm not really thinking about cost more just the idea of crazy possibilities. I swear I'm not as stupid as I sound lol v

The LMG's they're looking to replace are the 5.56 variants (like the SAW) so the caliber is already pretty small. HK has been experimenting with 6.5 and 6.8 caliber projectiles without any degradation in heat management, but the HK design uses a rotating bolt that keeps heat buildup to a minimum and also allows the system to continue firing if a cartridge does not go off, the next link on the belt just pushes the dud out and onto the ground.

The Army test fielded the LSAT and it achieved level 7 technological readiness, which means that it passed staged trials, the next step would be operational trials. That means that the heat management worked fine. Quite a feat for a 9 pound LMG (M249 SAW is 17lbs).

I doubt it will happen due to budget cuts, the Army will likely just choose an evolutionary upgrade rather then a new system. The USMC is perusing caseless ammo instead of the poly case stuff so that puts them about 5 years out of a working model, but they just went to the M27 so they're in no rush.

-W

[guitar-nut]

People, get a grip, these are only guns we are talking about, not freedom or life or happiness.

And to address the original post, well, I need a tube fed AR about as much as I need an ***hole on my elbow.

[IntoForever]

This unconstitutional attempt at gun grabbing is based on a semi-automatic? Just put a valve on the gas feed tube and make a quick mount pump to cycle the next round. I've seen a pump AK during the last attempt at taking guns from law abiding citizens. Probably a lot cheaper than a full blown civil war.