Optimized Caliber

[BluntForceTrauma]

Article on full-auto requirements.

John

[Variable]

Article on full-auto requirements.

John

Long overdue in my book. Dual disconnectors make for a very sucky trigger pull. I was happy to scrape up a 4 position selector for my registered sear when I first got it (I'd never fired a burst contraption before). I couldn't pull it out quick enough after I tried it.

Burst length selector:

[stanc]

Article on full-auto requirements.

Hmm. I'm positive I read that very same article months ago.

The Army’s senior leadership decided to start issuing M4A1s last year...

Huh? The Army began issuing M4A1s back in 2006!

Is military.com caught in a time warp, or something? :confused:

[LRRPF52]

If they combine that with the SOPMOD Block II handguards, they'll be headed in the right direction. I would also like to see more mini red dot sights for those using dots, and 1-4x or 1-6x for those with magnified optics.

On another note, I've been working with a replica of the KAC PDW, and the small size of the mags for the 6x35 cartridge have really got me thinking about the logistics advantages riflemen would have with that cartridge. I could carry 18 mags easily, they are so small. If you pushed the 65gr 6mm projectile out of a 16" barrel, I bet you could get around 2800 fps. Do an 18" bullpup and you'd get maybe 2860 fps, but that's assuming a linear return on barrel length.

Have LMG gunners and DM's with Grendels, and riflemen with the 6x35, and you could see a significant logistics chain longevity increase over the 5.56/7.62 system. I think powder, case, and projectile technology are to the point where we could see gains over both legacy cartridges for an enhanced 2-caliber system. You have got to see how small these KAC PDW 30rd mags are, and that thing spits out a 6mm projectile from an 8" or 10" barrel with substantial energy.

[JASmith]

I don't need to run calculations to tell that, for the same velocity, a 65 gr 6mm bullet will be less effective than a 62 gr 5.56 bullet. This is certainly true of barrier defeat and is true in wound channel generation.

My impression is that, absent an implementation in a weapon that clearly satisfies the size, weight, and ergonomic needs of the rifleman or for support troops, that a debate on this cartridge will go much the same way as all the other 5.56 replacement discussions.

Bottom line, the weapon/cartridge combination trades a little terminal effectiveness for slightly increased round count and smaller weapon, BUT not enough to make a compelling difference.

[stanc]

On another note, I've been working with a replica of the KAC PDW, and the small size of the mags for the 6x35 cartridge have really got me thinking about the logistics advantages riflemen would have with that cartridge. I could carry 18 mags easily, they are so small. If you pushed the 65gr 6mm projectile out of a 16" barrel, I bet you could get around 2800 fps.

Have LMG gunners and DM's with Grendels, and riflemen with the 6x35, and you could see a significant logistics chain longevity increase over the 5.56/7.62 system. I think powder, case, and projectile technology are to the point where we could see gains over both legacy cartridges for an enhanced 2-caliber system. You have got to see how small these KAC PDW 30rd mags are, and that thing spits out a 6mm projectile from an 8" or 10" barrel with substantial energy.

But not much velocity (only 2425 fps / 10" barrel). However, it is an interesting idea, as it would permit a significant reduction in weapon and ammo weight.

Personally, I think it might be better if the short, stubby bullet were to be replaced by a long, streamlined projectile (which would still weigh 62-65gr with a steel or steel/copper core).

[stanc]

Is this hinting at military use of 6.8 SPC in the near future?

[COLOR="blue"]"The military/LE market is...very deliberate, slow to change.

It took this long for 6.8 to turn a corner that needed to be turned.

6.8 in testing...is by far the most capable and somewhat perfect round for modern military and LE missions. Now it will be affordable and competitive with 5.56.

This ammo is loaded to military specifications with crimped sealed primers, case necks, visible annealing."[/COLOR]

(Also note the 30-rd 6.8 P-Mag.)

http://forum.lwrci.com/viewtopic.php?f=2&t=11314

[Tony Williams]

I very much doubt it. I can't see anything being adopted as a straight replacement for 5.56mm - the military has too much invested in it and refuses to admit that there's any problem with it.

What there is interest in is a cartridge which can reach out as far as 7.62mm while weighing a lot less. The 6.8mm Rem can't deliver this - it doesn't have the range - but the 6.5mm Grendel could. Of course, if such a cartridge were adopted to replace the 7.62mm MGs and rifles at squad level, there wouldn't be any point in carrying the 5.56mm as well, would there?

[LRRPF52]

There is still plenty reason to have carbines chambered in 5.56, since a Grendel load that is capable of replacing the 7.62 NATO for range and penetration will have all the effects you don't want at close range:

Too much recoil
Too much penetration for Close Quarters
Too much weight penalty on the rifleman

You would need a separate light loaded round.

[stanc]

I can't see anything being adopted as a straight replacement for 5.56mm - the military has too much invested in it and refuses to admit that there's any problem with it.

That's been the case so far. However, there's a post today on 68forums that seems more than just a hint at military use:

[COLOR="blue"]"These mags were not developed for the civilian market.

The design criteria: 1) will not lock into a standard magwell for those units that run 6.8 alongside 5.56 and 2) match the magazine geometry of 5.56 with a fatter cartridge for improved feeding reliability.

In addition, at my suggestion, the maximum COAL was increased...

There is a lot more to this than is public at this time. More information should be released in the next few weeks."[/COLOR]

http://68forums.com/forums/showthread.ph...post298959

[bwaites]

So, now there will be ANOTHER 6.8 standard, with longer mags and longer COAL. If I were considering this route, I think I would have made it long enough to use some of the longer .277 bullets, without giving up powder space. 2.30 doesn't gain enough space to justify a whole new magwell and specification, at least not to me.

But...I don't own a 6.8 yet, so maybe they have their reasons!

They are going to have to find someone who will shepherd this through SAAMI as a completely new cartridge, I'm thinking.

[stanc]

2.30 doesn't gain enough space to justify a whole new magwell and specification...

That's true. But, the reason for the new mag well is the need to accommodate a P-Mag designed for the fatter 6.8 SPC cartridge case. While they were at it, they took the opportunity to increase length enough so that SPC II ammo (such as offered by Wilson Combat) could also be used.

Being able to use 2.30" loads is just a nice "plus" that could be incorporated with minimal effort and expense. To go longer would entail a much more extensive redesign of both upper and lower receiver assemblies, resulting in an "AR-12.5" platform.

[Variable]

Meh, maybe they got somebody to bite. It wouldn't be the first time if they got stood up for the dance though. Guess we'll have to wait and see.

[LRRPF52]

Jordanian Secret Service has purchased 6.8 SPC PDW's from LWRC, and there is a totally different lower/upper receiver set on that PDW. The Middle Eastern nations with minority rulers buy all kinds of crazy weapon systems from different countries all the time. It's like a sampling of arms from around the world. You'll see various rifles from H&K, Steyr, the US, former Warsaw Pact, Israel, South Africa, FN, etc.

Their logistics would be a nightmare if they had any. Most of their aviation is maintained by US contractors working for big money after a term or two in the Air Force or Army, or working for one of the aircraft manufacturers/subcomponent manufacturers.

To infer that the 6.8 is gaining widespread military adoption because of the Beduin King's body guard service in Jordan is a bit of a stretch. The Grendel will do everything that the 6.8 will do, even from short barrels, so between the two cartridges for consideration for military use, the Grendel makes way more sense. I still don't see a huge need for anything other than a 5.56 in a PDW though, unless you go below a 10.25" barrel length, which is an extremely small niche market anyway. 10", 11.5", and 12.5" 5.56 carbines generate plenty of velocity, despite what all the claims have been.

There is zero reason to deviate from 5.56 in a carbine for military use. The biggest demand is in quality range time, which is not currently supported by most of the military. Allocation of range and ammo resources, compounded with a lack of institutional prioritization of true practical marksmanship are the main issues. Adoption of a new caliber for carbines would only exacerbate the current situation.

[Schwag173]

A subjective example, but a lifelong friend is a career Army officer that related a conversation he had with another officer about a year ago. The second guy headed up what is essentially the Army's 'future small-arms' office. According to my friend, the head honcho was "not even a 'gun-guy'," and expressed that the Army has zero interest in a new cartridge. With the draw-down of our overseas deployments and with the crappy economy, I (sadly) foresee that Uncle Sam will continue as before.

[Variable]

I still don't see a huge need for anything other than a 5.56 in a PDW though, unless you go below a 10.25" barrel length, which is an extremely small niche market anyway. 10", 11.5", and 12.5" 5.56 carbines generate plenty of velocity, despite what all the claims have been.

I don't keep up with the 5.56 much anymore since we just use whatever we're given at work, but what is the best general purpose "serious" ammo these days? I still have Mk262 Mod 1 for my personal 6933, but we don't get issued it and I don't have much left.

[Schwag173]

A subjective example, but a lifelong friend is a career Army officer that related a conversation he had with another officer about a year ago. The second guy headed up what is essentially the Army's 'future small-arms' office. According to my friend, the head honcho was "not even a 'gun-guy'," and expressed that the Army has zero interest in a new cartridge. With the draw-down of our overseas deployments and with the crappy economy, I (sadly) foresee that Uncle Sam will continue as before.

Here's an article about the new carbine being sought. No mention of a new cartridge. I wish it were different; I'd love to see something like an HK416 in 6.5 Grendel adopted.

http://www.military.com/news/article/gun...ompli.html

[bwaites]

Schwag, have you played much with the HK416? I've seen and handled them several times. While the idea seems great, the actual shooting experience was very disappointing according to friends whom I trust in such things.

I thought the ergonomics were inferior to the AR, with the weight in the wrong places.

Truthfully, I still haven't found one of the new rifles that I think is a real step forward in the race. Some of them have some interesting features, but they all have drawbacks that take them out of the running as far as I am concerned. (That doesn't mean I don't want them, it just means I don't seen them as a real step forward!)

The AR is so modifiable, that you can make one that will just about be perfect for what you may want. The new rifles, not so much. I think its because they are designed by committee, and thus are a series of compromises. When you look at the great military rifles of the past 100 years, most are basically one man designs....the Garand, the AR, the Kalashnikov, etc.

[Tony Williams]

Here's an article about the new carbine being sought. No mention of a new cartridge. I wish it were different; I'd love to see something like an HK416 in 6.5 Grendel adopted.

http://www.military.com/news/article/gun...ompli.html

Thanks for the link. The conclusion is no great surprise - I think that most observers expected that to happen as soon as they realised that an M4 improvement programme was going to run in parallel. I mean, how can any new conventional 5.56mm carbine realistically be so much better than an improved M4 (with all the changes made to it that the Army wants) that it's worth the cost to change?

[LRRPF52]

I don't keep up with the 5.56 much anymore since we just use whatever we're given at work, but what is the best general purpose "serious" ammo these days? I still have Mk262 Mod 1 for my personal 6933, but we don't get issued it and I don't have much left.

If only 2-legged dogs are to be shot, M193 works awesome. If a certain level of barrier penetration is desired, M855 is not a bad round, and still has excellent wound ballistics since it has a thin jacket as well. Wolf has very thick jackets, and is lower-powered, so it is not a good wound-producer. Many of the civilian 55gr bullets don't have thin jackets, so who knows how they would perform.

Within 150yds, I like bullets like the M193 and M855, or the LE Winchester SXT's, ballistic tips, and bullets designed to come apart. The 77gr SMK's and Scenars are good for distance work, and making an SBR run more reliably due to the bering surface and weight providing more resistance, and consequently more back-pressure for the gas circuit.