Requirements for Replacement of Currently Issued 5.56 M-855 and 7.62 M-80.

[JASmith]

One caliber vs two, or three . +..

The last several posts shed good light on some long-standing questions.

I have my own prejudices about what might be possible and have voiced them in previous posts in this and other fora.

What I have learned is that we don't know yet what the over-riding issue(s) will be when the opportunity for doing something new arises.

So, we should continue meeting the challenge Gene threw down NINETY+(!!-EEK!!) posts ago. Once we are able to sort out things like trajectory, the range dependency of required, when we need to stop vehicular IED's, etc., we can see where the technical requirements take us.

Overriding considerations like cost, custom, and plain old-fashioned prejudice will certainly influence the final outcome. So, ALL the cartridge families we define, including the current set, should be considered.

Hence, I am prepared to accept a cost-driven solution that concludes the current mix is pretty good. I can also see the set of constraints Tony has outlined leading us to a single plastic-cased cartridge with multiple loads. The "3-cartridge" model is an intriguing variation that should be tested against the needs we define.

In the meantime, I'm hoping to get a revised trajectory statement that accounts for more of the comments that were presented, and to get a draft barrier penetration requirement statement sometime in the next few days.

[Tony Williams]

I have just received some feedback from interviews with a dozen British infantrymen just back from Afghanistan, who were specifically asked about the calibre issue.

They are comfortable with the performance of the 5.56mm out to 200m, the main problem at longer ranges being scoring hits, partly because the little bullets are so affected by wind drift. (Comment: their standard rifle does of course have a 20.5 inch barrel.)

They dislike the L85A2 because it is so heavy and unergonomic; for those reasons, they'd rather have an M16A4. Their opinion of the L85A2 has put them off all bullpups. (Comment: a pity, since there are much better bullpups around. It is of course possible that if they did get the M16, they would start complaining about the length!)

They very much like the 7.62mm guns: the L7 GPMG (M240) and the L129A1 rifle, which are very effective at all ranges. However, only 30-40% soldiers were capable of getting the best out of the L129A1 in terms of long-range accuracy.

Given a straight choice between 5.56mm and 7.62mm weapons, ALL of them would rather carry 7.62mm, despite the weight and recoil issues.

They would be delighted if someone came up with an intermediate cartridge and weapons which matched the performance of the 7.62mm with significant reductions in weight and recoil. However, they have no experience of such a round and would need to have a lot of successful hands-on experience with the weapons before they would accept it.

[stanc]

I have just received some feedback from interviews with a dozen British infantrymen just back from Afghanistan, who were specifically asked about the calibre issue.

They would be delighted if someone came up with an intermediate cartridge and weapons which matched the performance of the 7.62mm with significant reductions in weight and recoil.

What aspect(s) of performance do they want matched? Just trajectory and drift, or terminal effects, too?

[Tony Williams]

What aspect(s) of performance do they want matched? Just trajectory and drift, or terminal effects, too?

The phrasing was: "as lethal as 7.62mm to 1000 metres"

[LRRPF52]

stanc,

The Garand was the standard service rifle, but was augmented healthily with a mix of M1 Carbines and Thompsons in key leaders' and riflemens' duty positions, in addition to BAR and M1919 gunners. That was a broad mix of weapons capable of CQB out to beyond riflemen distances. A single caliber would have short-changed them, however, they had a logistical nightmare on their hands.

The extreme jerk to the opposite end of the spectrum with the 7.62 NATO single caliber system failed miserably. While a 7mm Enfield would have served the Garands, BAR's, & M1919's very well, it would have hurt the M1 Carbine and Thompson.

Looking into the future, the Russians have fielded the An-94, which is actually their official service rifle since 1986-from what they have told me, but only one regiment has it since there is too much political loyalty to the Kalashnikov design and the "new" AK-100 series. The An-94 is designed to defeat hard armor by firing the 1st 2 rounds on auto at 1800rpm, after which it transitions to a conventional cyclic rate like the AK-74. It is chambered in 5.45mm, and places those 2 rounds within a few centimeters of each other at 100m, so that an armor plate is in a more elastic state when the 2nd round hits, blowing through it.

There doesn't seem to be much knowledge of...or interest in it, since it requires more extensive manufacturing, with a receiver that recoils within a receiver (heavy).

LRRPF52

[LRRPF52]

Fella's

It doesn't take a tour to the Stan to tell you that 5.56 NATO, or pretty much any service rifle cartridge, gets blown around by the wind at distance. Even my .260 is affected by heavy winds, as are .300 Win Mags. The only cartridge I know of stepping up that displays significant resistance to winds is the .338 LM, so even with a 130gr or 140gr 7mm or 6.5mm going 2600-2800 fps, you will still need to be trained in wind-doping to make a hit on-target. Guess how many 1st-term soldiers are trained in wind-doping skills? Less than a fraction of a percent, and those are the very rare few that get any precision rifle training in a sniper billet, or designated marksman course, as the US has been implementing. Proper wind-dope training means on the range, not in some classroom.

The US Marines actually train for wind-doping, but their ranges were traditionally stress-free until recently, when the Corps has undergone drastic changes to their entire marksmanship program. Friends of mine who are in the Marines tell me it's actually fun/stressful and practically-focused, in addition to the traditional course of fire they did all along.

Whether a guy has an M4 or an L129A1, if he can't dope the wind, he's only distributing harassment fire, which only encourages the goat-rapers. Any references to the lethality of 7.62 NATO at 1000m will almost always be from GPMG's in most environments, especially since the wind can be horrendous in open terrain. Equipping the whole lot of 1st-term soldiers with L129A1's will only produce more 7.62 NATO harassment fire, and really suck when it comes time to kick in mudhuts. Muzzle blast from that weapon is guaranteed to cause some serious hearing damage, above and beyond 5.56 NATO, since you need double muffs and plugs to deal with 7.62 in enclosed spaces. It feels like getting punched in the nose when a 7.62 rifle or MG is being discharged in the room you're in.

The LMT .308 (L129A1) is also a beast of a rifle/carbine when you pick it up, unless the UK got some pencil weight barrels, but all the pics show to me pretty hefty pipes that look exactly like the one my friend has. The 16" LMT .308 feels as heavy as my 22" .260 with a very hefty barrel. My barrel is a heavy contour that tapers from 1.2" down to a .880", then steps up to the gas block at .936", and is .9" out to the muzzle. Not fun for a rifleman to carry. When I felt the LMT, I was immediately soured by its weight, which is heavier than normal due to the increased length barrel extension used in the monolithic upper receiver.

While Grendels would make the load lighter than .308, they would be wasting harassment fire at the enemy, so there is a more important training factor to this equation than caliber if you want to increase hit probability with any existing caliber that will fit into a practical rifleman load-out, which 7.62 NATO is not. The only way around this is new technology with near hyper-sonic projectiles that defeat wind deflection with extreme velocity, which might not be a bad avenue to start looking down if armies refuse to conduct worthwhile marksmanship training.

LRRPF52

[stanc]

The Garand was the standard service rifle, but was augmented healthily with a mix of M1 Carbines and Thompsons in key leaders' and riflemens' duty positions, in addition to BAR and M1919 gunners. That was a broad mix of weapons capable of CQB out to beyond riflemen distances.

Yes, there was. However, the key phrase above is "augmented" by Carbines or Thompsons. There were still far more Garands in a rifle squad, than those two weapons. Surely you don't think the (10?) rifle-equipped troops left CQB to just the one guy in the squad who had a Tommy gun?

The extreme jerk to the opposite end of the spectrum with the 7.62 NATO single caliber system failed miserably.

Indeed. But, that's because they insisted on a full-power cartridge, not necessarily because a one-caliber system can't be achieved with an intermediate-power round. The Chinese came so close, with the 5.8x42. They just went a little too small.

[stanc]

The phrasing was: "as lethal as 7.62mm to 1000 metres"

Is it possible to achieve that? And if so, can anybody hit a gel block at that distance to demonstrate it's just as lethal?

[LRRPF52]

stanc,

I agree, the 5.8x42 has proven whimpy for them out of LMG's, which is why I think we all agreed that 6mm is the basement on this one. The topic of sabots has got the gears turning again because I have been interested in them for many years...especially in an LMG, where it's common to mix a certain type of bullet with another...i.e.: tracer to ball mix. If a hyper-velocity sabot-launched AP round were included in that mix, or proved to be viable enough for the primary ammo type, that would be a game-changer. If they're getting rifle velocities out of the 6.5x25, imagine what a 5.56 would do...

Before the Great War of 1914-1918, several advancements in weaponry had taken place: the machinegun, repeating rifle, the armored car/tank, the aeroplane, guncotton, & the submarine. I think this generation is headed into another stage like that, where introduction of certain technologies will make things from the last century obsolete and painfully inferior on the battlefield, to the surprise of him who wasn't vigilant enough in pursuing his defense posture intelligently and aggressively. Many of those inventions were pioneered by free-thinking experimenters in their family shops or garages, or nutty professors like Nobel.

The Chinese and Indians have literally billions of people to siphon from to drive these developments, while Russia rakes in billions in profit from the sale of natural gas and oil. Since China and India don't have enough real estate or food production to feed their people, the stress has to be relieved at some point. Need I mention the vacuum for advanced military hardware that exists in the Middle East? Saudi Arabia and Dubai have ordered the largest Foreign Military Sales schedules in the history of mankind, totaling over $120 billion.

He who introduces a system to defeat yesteryear's designs and capabilities will have a decisive edge on the future battlefield. On a more primitive note, I ordered some Lapua 144gr for some tests...

LRRPF52

[z06man]

I want to express my appreciation to the contributors to this thread. It has been very interesting and educational. It's kinda like sitting in on a R&D meeting.

Also in reference to creating hypervelocity projectiles, what speed do you consider hypervelocity? My understanding is that we are near the limits of velocities with modern smokeless propellents around 4000 fps for bullets due to the fact that they have a maximum expansion rate in the 5000 fps range.

[stanc]

On a more primitive note, I ordered some Lapua 144gr for some tests...

Excellent! Looking forward to the results.

On a related note, I've wondered for some time how to do some valid comparative testing on 6-7mm bullets. The trouble is, insofar as FMJs are concerned, none of those available are of the same type or have weights proportional to caliber.

6mm ----- 80gr flat base in .243 Win.
6.5mm -- 140gr boat tail in 6.5mm Swede.
7mm ---- 140gr flat base in 7mm Mauser.
7.62mm - 147gr boat tail in 7.62mm NATO.

Today I came across Federal's "Fusion" line, with bonded-core, (protected?) soft-nose bullets, in the following calibers:

6mm ----- 95gr in .243 Win.
6.5mm -- 120gr in .260 Rem.
7mm ---- 140gr in 7mm-08 Rem.
7.62mm - 150gr in .308 Win.

I'm not sure just how worthwhile it'd be to test them, but the fact that all have the same boat-tail design, with weights roughly proportional, and made by the same manufacturer, loaded in the same basic case...

[LRRPF52]

stanc,

I was actually looking through Midway's selection of protected tip, bonded core bullets yesterday as well. They might be a good baseline from which to drill into the core, then insert a steel or other hard metal rod.

What I'm addressing with the various duty positions is the fact that a very large percentage of soldiers would be encumbered if they were to be saddled with anything heavier than an M4, with less ammunition capacity. That includes...

* Combat Medics
* Forward Observers
* RTO's
* USAF TAC-P's
* Assistant Machine-Gunners
* Ammo Bearers
* Javelin Gunners
* Platoon Leaders
* Rifle Squad Leaders
* Fire Team Leaders
* 1st Sergeants
* Company Commanders
* Platoon Sergeants
* Combat Engineers

I could go on, but you see the point. If you really want to hear the moaning and complaining, issue these guys something heavier than an M4, with heavier ammunition, who will most unlikely or never be trained in wind-doping skills, right along with the riflemen who rely on them for all kinds of support. I can see the Gun Rag articles now..."Everyone remembers the days of the wonderfully-lightweight M4 carbine, (a superb carbine with a nasty little cartridge with devastating wound effects, highly-preferred by Special Forces soldiers) before the Army came along and adopted this horrible monster..."

LRRPF52

[LRRPF52]

Oh, I also have the new unubtanium Lapua .260 Rem brass, so this will be fun on a few levels for me. I've been necking-down Winchester 7mm-08 brass, since it is harder than the Remington .260 brass, and I've gotten up to 4 re-loads out of it running pretty hot loads. I'm pushing 123 Scenars at 2960, and 130 Berger VLD's at 2850, with cratering primers, and light ejector swipes. I reached my, "Ok, this is too far..." load when the naked 130's pierced primers and my chrono made huge jumps and drops over 100 fps in the spread, so I came down from that quite a bit. I had to dig the remains of some primers out from around my firing pin when I broke her down, and my firing pin retaining pin was badly disfigured. I'm thinking if I got my firing pin hole bushed and the pin matched to it that I could prevent that, but I'm already well over book figures. The AR10 bolt and barrel extension can take a lot more beating than a 5.56 one...

I'll have to take it easy with the 144 FMJ's, and drop down quite a bit for starting loads. I'm using N540 for the .260 right now, and getting .75 MOA with my initial loads, so it has some room to be tweaked.

LRRPF52

[stanc]

I was actually looking through Midway's selection of protected tip, bonded core bullets yesterday as well. They might be a good baseline from which to drill into the core, then insert a steel or other hard metal rod.

I was thinking similarly, wondering if there might be bullets which could be used to emulate the M855A1/M80A1 projectiles. Figured that perhaps Federal's Trophy Bonded Tip might be usable: pull the plastic tip and drill out the lead core, but leaving the solid base unaltered.

[stanc]

What I'm addressing with the various duty positions is the fact that a very large percentage of soldiers would be encumbered if they were to be saddled with anything heavier than an M4, with less ammunition capacity. That includes...Combat Medics, Forward Observers, etc.

I could go on, but you see the point. If you really want to hear the moaning and complaining, issue these guys something heavier than an M4, with heavier ammunition, who will most unlikely or never be trained in wind-doping skills, right along with the riflemen who rely on them for all kinds of support. I can see the Gun Rag articles now..."Everyone remembers the days of the wonderfully-lightweight M4 carbine, (a superb carbine with a nasty little cartridge with devastating wound effects, highly-preferred by Special Forces soldiers) before the Army came along and adopted this horrible monster..."

Heh, heh, heh.

Yes, I do see your point. And IIRC, LR1955 has said that most infantry riflemen -- even if given a more capable cartridge -- would still be unable to hit long range targets.

Nevertheless, there seems to be a signifcant number of (US and UK) troops who are calling for longer "reach" from their individual weapon than 5.56 can deliver. Are they to be ignored?

What if a new cartridge can be created that doesn't impose a great weight penalty, and thereby (maybe) avoid being a "horrible monster"?