gatnerd

Military Guns and Ammunition

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This is intended for people interested in the subject of military guns and their ammunition, with emphasis on automatic weapons.

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NGSW Phase 2 Consolidation and info   Small Arms <20mm

Started 30/8/19 by gatnerd; 284003 views.
nincomp

From: nincomp

26-Oct

If I recall correctly, Emeric's neckless 5.56 was fired in a rifle with unmodified 5.56x45 or .223 chamber.  The TV neckless is designed to be shot with a chamber optimized for it.

There are essentially two different "neckless" concepts being discussed on this site, and the older one dates back a decade or more.  This is the one that Emeric has mainly discussed which is intended to permit longer-ogived bullets to be fired in existing weapons.  The 7.62x51 and 5.56x45 cartridges in normal brass cases are limited to relatively short ogives.  In Emeric's "retrofit" design, the neck is removed to allow the longer ogive of a more streamlined bullet to reach completely back to the shoulder of the cartridge.*   Unfortunately, this means that the full-diameter shank of the bullet must travel a significant distance (the distance formerly occupied by the neck material + original freebore) before it becomes supported by the rifling and bore.  We had suspected that there would be an accuracy penalty, but only recently has Emeric had time to actually test real world examples.  It is possible that future optimizations, including some to the projectile shape, might increase accuracy.

The second neckless concept is the one being used by TV.  In this case, the barrel is optimized for the cartridge, with the chamber's throat being moved back to permit a more normal jump to the lands.  This style of neckless cartridge should be significantly more accurate.

* At one point, when moderate-recoil General Purpose Cartridges (GPC's) were a major topic on this forum, I had suggested that a  lower-recoil GPC-style cartridge could be shot from a standard 7.62x51 weapon.  The cartridge would be neckless, permitting the use of a higher-BC 7.62 projectile and less propellant.  The thought was that the lighter, lower recoiling neckless round would be able to match energy of a standard NATO 7.62 round at long range (800m or so).  As it turned out, I was not the first person to think of the idea, and Emeric had already applied for a patent on it.

stancrist

From: stancrist

26-Oct

roguetechie said:

...guns and ammo just did a feature on their gun and is talking about 1 moa consistently including flyers.

5.2 kg though with an MRDS which is a big oof.

A big oof, indeed. 

Thanks for the info.  I don't have access to G&A. 

Is it possible to shoot 1 moa with a MRDS, or did they have a different sight installed for the accuracy test?

PRM2

From: PRM2

27-Oct

I've found the cheapest way to get access to G&A is through an app on my tablet called 'Readly'. It costs about £9 a month here and has saved me a shed load of money and waste of paper in not buying loads of car, motorcycle and aviation magazines, which would only be read once. They have back issues of G&A going back to the end of 2014 and also have a few other firearms related magazines. You can normally get a deal for the first month for free to see if you like the magazine selection. The disadvantages are you don't get a permanent copy and loose access when the subscription stops.

gatnerd

From: gatnerd

27-Oct

That is a good deal.

I just bought the digital Nov 2021 issue for $5. Some maddening system where you buy it and they email it to you 24hrs later for some unknown reason.

Once it arrives I’ll get screenshots of the relevant TV / RM277 section and share it here so everyone can read it.

Gr1ff1th

From: Gr1ff1th

27-Oct

Excellent, I'm looking forward to it

roguetechie

From: roguetechie

27-Oct

I have the whole article as screenshots. I just wasn't sure if you were ok with me sharing them. Since you are, I will upload them later tonight to my Google drive and drop a link in here to that specific folder.

(This avoids Delphi making it an article with print sized well for ants to read)

gatnerd

From: gatnerd

27-Oct

And here is the article as embed images for those reading on their phone. Guns & Ammo did a great job - I plan on re-subscribing.

poliorcetes

From: poliorcetes

27-Oct

Thank you, hombre!

135 gr, 3000 fps - 3600 J at the muzzle

and peak pressure of 65000 PSI, quite lower than the alternatives

roguetechie

From: roguetechie

27-Oct

A very important thing to note is that TV can absolutely ratchet the pressures up if necessary AND they're getting enough of an efficiency bump in a cartridge this size to potentially get a little more MV out of any given peak pressure.

These are both fairly significant factors in making TV case technology one of the safer bets.

They also have their case manufacturing technology streamlined enough to make scaling production doable in a short interval.

I'm not super sold on the Lonestar/GD rifle but everything else they have is damn tempting.

On the note of TV pushing the pressures up, the legacy 240's we have (and the Barrett LWS I'm not so sure on mk48/240L) already have bolts and carriers theoretically safe to damn near 100k psi.

With the wider economic and political situation the way it is, I'd almost be inclined to tell sig and TV to suck it up, take the best of both programs (IF we can physically make enough Delta p cans!), and dump a moderate amount of money turning legacy 240's etc into 6.8 slingers while also doing a pure fleet back end swap to 5.56 and 7.62 neckless in the legacy fleet for anything that really can't do the high pressures.

This buys us breathing room, time to spool up, and hopefully results in people not blowing up guns by trying to chamber hot shit in stuff it doesn't belong in.

If you really want to go full bonus points, make a new standard lightweight link pattern for all the conversion guns to eke out just a bit more weight savings and possibly some long term cost savings too.

There's a few different ways you could do this in stages to make the workload on depots armorers etc more manageable.

Another thing I'd probably look at doing is a new optic or two that aren't quite ngsw fc level complexity but do run digital reticle projection and a ballistic comp onboard or an easy interface to swap the reticles depending on the exact ammo being used.

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