Back to 7.62x51mm... is there a method to this madness?

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charlielima223

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Unread post08 Aug 2017, 02:34

Through my time in service I always heard the saying, "method to the madness". Sometimes when I looked hard enough or when I was finished with what ever task or objective I would finally see the method behind all the madness. Other times I was scratching my head wondering "what the F?". Recently the US Army put out an solicitation for a 7.62x51mm rifle to be used by active duty infantry units...

https://kitup.military.com/2017/08/new- ... rifle.html

http://www.military.com/daily-news/2017 ... rifle.html

http://www.thefirearmblog.com/blog/2017 ... d-us-army/

This "interim combat service rifle" as it is to be called, was in response to the concerns of speakers against the current 5.56x45mm (Ret Gen. Scales, being the most vocal) is unable to defeat modern body armor as well as being out ranged (which I will get into later)

http://www.thefirearmblog.com/blog/2017 ... ody-armor/

https://www.armed-services.senate.gov/h ... f-the-army

However there already exists 5.56 and NATO 7.62 rounds that can defeat body armor. This is seen in the form of (albeit the unicorn of US Military ammo supply chains) M995 for 5.56 and M993 for 7.62, commonly referred to as "black tip". These round have tungsten cores designed to defeat lightly armored vehicles and most forms of hard body armor.

However this like looking for a solution for a problem that either doesn't (really) exist or making up a problem that doesn't have a practical solution.

Current body armor fielded by US Troops are rated at level IV and higher. The ESAPI plates designed to defeat hits from 30-06 M2 AP rounds. In theater numerous lives of US Troops have been saved by use of ESAPI plates in our current body armor. Accounts of soldiers and marines taking numerous hits from 7.62x39 and walking away from 7.62x54R from both PKM and SVD.

according to description, he was shot 4 times.


this infamous footage showed just how good our body armor is when a US Army soldier took a direct hit from an Iraqi insurgent sniper using an SVD.


So the claim is that using a larger 7.62x51mm round is capable of defeating modern body armor when its already being seen that modern body armor (at least the stuff that we use) is fully capable of defeating 7.62 rounds. This is of course done all in the sake and name of "overmatch".
During military actions in Afghanistan there, US and Coalition forces faced a problem; entrenched Taliban/AQ/Mujahadeen/insurgents in a fixed position. Often times these fixed positions were in higher elevations. Hill top to hill top engagements between Coalition and insurgents became a somewhat regular basis. This drove the US military to reintroduce the M14 back into circulation with combat units in Afghanistan as well as in Iraq (Iraq was for another reason which I wont get into for the sake of this ranting).

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This also drove the adoption of the M110SASS along side the M14

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These weapons were issued at mostly at squad level. The issue at the time was that with current platoon or squad make up; the only weapon that was capable of engagements that extend beyond our current 5.56 platforms (M249 SAW, M4/M16) was our M240. What was needed was a rifle that could be issued at the squad level and extend the engagement range when needed. To which these two systems (M110SASS and M14) fulfilled their role to great success often as a DMR.
This is where the argument of "overmatch" comes in. Many people will point to the case of Afghanistan as "proof" of the "failings" of the 5.56x45mm round/cartridge and it's platform. However the vast majority of engagements in Afghanistan was still well within the listed engagement range of our 5.56 platforms. The times when US troops were out ranged was when they were engaged by insurgents from a higher elevation using plunging fire or with heavy crew served weapon (DShK).

However there is more to it...

Before all this the US Army put out a solicitation and RFP for something called the Compact Semi Automatic Sniper System (CSASS) which H&K won with their variant of their G28/HK417 (personally I would have thought the KAC's M110K1 better as it is already being used within SOCOM and has more parts compatibility with current M110) to move onto the next phase of trials. There is talk and mention within some circles however that the H&K submission is not performing to specifications and standards and that it is actually more expensive then initially pitched/advertised the US Army. The last part comes as no surprise as the M27 IAR (a variant of the H&K416) already cost 3k per unit... that is before the cost of optic, bi-pod, or what ever stuff that is attached to or issued with the weapon. That is double the base price of a standard M4A1. Personally I am seeing this as a push for the CSASS into a wider role as a way to cover up the failings and cost of the weapon.

There also the case of lethality and barrier/armor penetration of the current 5.56x45 used by the US Army. I will get more into that later but that is a bit of another topic.

Personally I think this is a really F-tarded decision with heavy amounts of Good Idea Fairy dust all over it.
1. Less ammo to be carried by the individual soldier for the same or more weight
2. Heavier individual weapon for an already overburdened troop. Typical load out for operations already exceeds 50lbs and comes very close to 80lbs depending on operations.
3. People are confusing practical engagement ranges (what the soldier is capable of in actual combat conditions) to listed engagement ranges (what you're able to do at the rifle range for BRM quals or a relaxing day at the range).
4. Money and time spent improving the M4A1 and 5.56x45mm to be more effective now all for naught.

Here is an interesting wrinkle. While Big Army as pushing for a heavier 7.62 rifle, USASOC (US Army Special Operations Command... US Army Special Forces aka Green Berets and SFOD-D) seem to be wanting to keep their M4A1s and improve upon them with COTS (commercial after market parts)...

http://soldiersystems.net/2017/05/08/us ... its-m4a1s/
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h-bomb

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Unread post08 Aug 2017, 05:06

I was think of the M110 as I was reading this, glad you mentioned it. All 8.4 lbs for the M110K2...
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f-16adf

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Unread post08 Aug 2017, 15:38

I understand for CQB the M4 barrel is 14.5 inch, if they want the 5.56 to have improved penetrating power why don't they adopt a longer barrel/ with a free float handguard (cost)? I understand the M-16's 20 inch barrel is too long, yet it has improved velocity over the 14.5 inch model. Maybe around 17 inches or even 18; Or I guess they could try a bullpup (I have fired the Tavor, but not too impressed by it).




I have only fired the M1A1 and SCAR 17S (civilian use) in 7.62, both fine weapons. The SCAR is a beauty, but VERY costly. The M1A1/M-14 is a classic.
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durahawk

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Unread post08 Aug 2017, 16:27

Before all this the US Army put out a solicitation and RFP for something called the Compact Semi Automatic Sniper System (CSASS) which H&K won with their variant of their G28/HK417 (personally I would have thought the KAC's M110K1 better as it is already being used within SOCOM and has more parts compatibility with current M110) to move onto the next phase of trials. There is talk and mention within some circles however that the H&K submission is not performing to specifications and standards and that it is actually more expensive then initially pitched/advertised the US Army. The last part comes as no surprise as the M27 IAR (a variant of the H&K416) already cost 3k per unit... that is before the cost of optic, bi-pod, or what ever stuff that is attached to or issued with the weapon. That is double the base price of a standard M4A1. Personally I am seeing this as a push for the CSASS into a wider role as a way to cover up the failings and cost of the weapon.


H&K products being expensive yet underperforming? Never.
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Unread post08 Aug 2017, 20:53

f-16adf wrote:I understand for CQB the M4 barrel is 14.5 inch, if they want the 5.56 to have improved penetrating power why don't they adopt a longer barrel/ with a free float handguard (cost)? I understand the M-16's 20 inch barrel is too long, yet it has improved velocity over the 14.5 inch model. Maybe around 17 inches or even 18; Or I guess they could try a bullpup (I have fired the Tavor, but not too impressed by it).


Even a longer barrel may not yield that much more penetration ; take a look at figure 2 at the bottom of the article. The difference between the 20" M16 (surely A2 or A4) and the M4 is the distance at which a concrete masonry unit is penetrated, roughly 100 vs 50m, otherwise, the performance seems equal against the 3/8" steel plate : https://www.americanrifleman.org/articl ... cartridge/

Also note that this level of penetration, 3/8" = 9.525mm at roughly 350m, is impressive ; that's way superior to the M80 ball in 7.62x51mm, with its 4mm penetration at 300m : http://www.inetres.com/gp/military/infa ... _ammo.html

Also, while the performance of the M80A1 is unpublished or very hard to find, you may want to take a look at what BAe has done : http://www.baesystems.com/en/article/ne ... ammunition

Note how the 5.56 Enhanced Performance Ball is close to the 7.62 High Performance Ball.

@charlielima223 : As you've quoted The Firearm Blog, I'd suggest checking out the many articles by Nathaniel F ; in one of his articles, he makes a compelling explaination about why the infantry platoon should ditch the 7.62 and get a hypothetical 6.5mm cased-telescoped round instead, at least for the MG in the weapons squad and also potentially for the automatic riflemen in the rifle squads : http://www.thefirearmblog.com/blog/2016 ... on-part-2/
Last edited by viper12 on 09 Aug 2017, 15:01, edited 1 time in total.
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Unread post09 Aug 2017, 01:17

A friend of mine has a Colt 6920 SOCOM (it's kinda like the military M4 but with the 16 inch barrel, a free float handguard, and of course no full auto. Really nice carbine and very accurate too. I always wanted an AR type rifle/carbine, was thinking of buying a Daniel Defense or BCM someday.

The SCAR 16 (5.56) is really nice but like its bigger brother, the 17S, is just way too much money. But it's a beauty-
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Unread post09 Aug 2017, 07:15

1% method, 99% madness. Our infantrymen are already massively overloaded (100lbs+ combat loads), to the extent that orthopedic injuries and disability are increasingly common. Any 7.62x51 round dramatically reduces the number of rounds carried per pound, either reducing the infantryman's combat endurance or further increasing his load, depending on whether or not an attempt is made to match the 210-round load standard with 5.56x45. Neither is an acceptable option.

Despite its less-than-remarkable terminal ballistics, I find 5.56 quite satisfactory as a standard-issue rifle cartridge. Its light weight allows a large number of rounds to be carried at reasonable weights, increasing the infantryman's endurance in a firefight. 7.62 gives that up in favor of...slightly improved terminal ballistics. With anything other than the awful M855, 5.56 has acceptable terminal performance, and is certainly not sufficiently lacking as to justify halving the infantryman's endurance. Of all the folks I know who have equipped themselves with modern arms and armor and train with them regularly, not one has elected to use 7.62x51. There is a very good reason for that.
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Unread post09 Aug 2017, 13:29

What they need is to push for smart bullets at the squad level and continue with higher velocity pea shooters for close-in work. The smaller caliber higher velocity ammunition is going to penetrate anything save for the most exotic kits out there, kits that are impossible for the enemy to field except in very limited concentrations.

Laser aimed projectiles have been shrunk to .50 caliber. So you have some fellas carry heavy grain smart rounds to take out heavier targets. Smoothbore and shorter barrel than a sniper rifle that can pinprick targets drastically beyond the range of the 5.56 yet powerful enough to go through common obstacles like cars and block walls. We used to shoot .50 caliber muskets at a little over 1000 fps. The heavy grain conical bullet had virtually no kick, but when it hit the kinetic energy was high enough to shred railway ties and fence posts. A purpose-built large grain bullet would add significant punch at higher pressures and with accuracy. With a high degree of assurance of a kill, you could justify something at the squad level in the .51 to .66 caliber range.

Computer aimed weapons will be filtering down to the squad level eventually, too. Pop-up tripod mounted guns that are remotely aimed by a human have uncanny accuracy with current technology. Stuff like this would have ended trench warfare instantly. Mobility is its weakness, but as a defensive weapon or for posting up on the fence line as the squad flushed out targets, it would have its place.
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Unread post09 Aug 2017, 16:15

6.8mm SPC II, problem solved. (Of course they'd still find a way to spend tens of millions of dollars "studying" an already well known and existing round. :bang: )
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Unread post09 Aug 2017, 20:30

Look at the Cased Telescoped Ammo.

In the most Recent PDF that I can find, it has a 6.5mm CT Cartridge that outperforms our current 7.62x51mm NATO in every Ballistic spec including weight of ammo.

There's no reason for this change to 7.62x51mm

We need to start ramping up for CT Ammo as soon as possible and start leveraging platform advantages and mass production capability.

CT Ammo is the future.

Plus we can optimize the new Rifles, Machine Guns, Bullets, Powder, etc.

http://www.dtic.mil/ndia/2016/armament/ ... illips.pdf

I already have program outline for replacing everything from PDW sized weapon all the way up to 20mm Anti-Material rounds.

Everything optimized for Maximum Magazine Volume, Muzzle Energy, Ballistic Efficiency, reasonable weight, maximum reliability, etc.

If we partner with our NATO allies, we can get better Mass Production Benefits / Unified and Shared Weapons Development costs.
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Unread post09 Aug 2017, 23:24

f-16adf wrote:I understand for CQB the M4 barrel is 14.5 inch, if they want the 5.56 to have improved penetrating power why don't they adopt a longer barrel/ with a free float handguard (cost)? I understand the M-16's 20 inch barrel is too long, yet it has improved velocity over the 14.5 inch model. Maybe around 17 inches or even 18; Or I guess they could try a bullpup (I have fired the Tavor, but not too impressed by it).



The issue between the carbine sized M4 and full length rifle M16 is a bit of a non issue now with current M855A1 EPR. The impetus for the US Army's wide adoption of the M4 (now M4A1 for active units) came out of experience and operations in Iraq. Before that most infantry units (other than airborne and air assault dedicated units) had a hodge-podge of M16 and M4s. Vehicle and urban operations demand a shorter weapon. What was found that the shorter barrel of the M4 reduced the performance of the older M855 (commonly referred to by troops as "green tip") which was optimized for the longer barrel profile of the M16. The reduced muzzle velocity of out of the 14.5inch barrel of the M4 resulted in inconsistent wounding effects as the 5.56 round is dependent on yawing or fragmentation to have the optimal effect on soft targets (people). Testing and field reports often showed that the M855 out of the M4 would "ice-pick" the intended target.

AARs coming out of Iraq and Afghanistan around the M4 and the M855 pushed the further development and fielding of the current M855A1 Enhanced Performance Round. The M855A1 addressed all the issues of the older M855 and greatly exceeds the M855 in all areas as well as being tailored for the M4 carbine...





https://www.youtube.com/watch?v=d8IvDPuVuho&t=230s

so the debate between a 14.5inch length barrel and the longer 20inch barrel is no longer existent should the M855A1 be a factor in it.
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Unread post10 Aug 2017, 00:29

You can get about 20-30% improvement in penetration comparing similar 5.56mm and 7.62x51mm rounds. So it's not trivial. On the other hand 7.62x51 comes with other trade-offs which make it less than ideal for the regular soldier. In any case, this tender is not for equipping every solider in a squad. It is likely for coming up with a more standardized approach to a marksman rifle as opposed to the many different types of guns used now.

To figure out whether its needed or not, one should consider what sort of body armor the enemy uses for their regular forces. Even most (if any) near-peer adversaries are not going to be as heavily armored as US Army soldier, and certainly none of what is faced in irregular forces are.

More important than terminal ballistics and penetration, in my opinion, is optics. The regular US soldier is so far ahead of any adversary in terms of optics and accuracy of long-range shooting that any paper-advantage in range of 7.62x39 or x54, is just academic. They can out-range you only on paper (or as charlielima223 says during engagements from elevated positions, but even then, they can't hit accurately).

charlielima223 wrote:Current body armor fielded by US Troops are rated at level IV and higher. The ESAPI plates designed to defeat hits from 30-06 M2 AP rounds. In theater numerous lives of US Troops have been saved by use of ESAPI plates in our current body armor. Accounts of soldiers and marines taking numerous hits from 7.62x39 and walking away from 7.62x54R from both PKM and SVD.


7.62x54R is a pretty s**ty round in terms of penetration, especially given the types of ammunition generally available to it.
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Unread post10 Aug 2017, 02:23

charlielima223 wrote:Through my time in service I always heard the saying, "method to the madness". Sometimes when I looked hard enough or when I was finished with what ever task or objective I would finally see the method behind all the madness. Other times I was scratching my head wondering "what the F?". Recently the US Army put out an solicitation for a 7.62x51mm rifle to be used by active duty infantry units...


Big Army believes that 5.56 & the 2.260" OAL cartridge are maxed out developmentally. Therefore the next jump in performance will require a platform with a longer action in order to accommodate a round with greater overall length.

They've focused on .264/6.5 - .277/6.8 as being the ideal diameter and the AMU has been testing .260 Rem, .264 USA & .277 USA for several years now. The belief is that it would be a hard sell to get Congress to sign off on both a new rifle & a new caliber at the same time. But if you get your new rifle first in a cartridge that is already well established in the system, it's a lot easier to get new barrels/bolts later to retrofit it to your 'ideal' cartridge that just happens to be the same OAL.

Ultimately this is a potential backup plan if CTA doesn't pan out. Lighter weight Polymer-Cased Composite cartridges are also part of plan B.

The Army also seems to have been somewhat scarred by the difficulty in engaging PKM/SVD armed troops at extended
ranges. I have no idea why there seems to be a prevailing notion that carbine equipped soldiers are supposed to effectively counter MG & DMR fire. I have even less of an understanding why the need for increased marksmanship training is getting swept under the rug.

To be honest there is a cynical part of me that wonders if it is someone's idea of a subtle means of scuttling the opening of combat arms to women. The average male soldier isn't going to be overly thrilled with the increased weight & recoil this is going to bring into the equation...just wait until the 5'4" 135 lb female troopers receive them.

sferrin wrote:6.8mm SPC II, problem solved.


6.8 SPC does nothing to address the two primary issues that the Army has voiced as being behind the potential move to 7.62x51, It's performance beyond 450m is poor & it does not provide an increase in armor penetration over current 5.56 loads. There is a reason that even 5th SFG (who sponsored it's creation in the first place) ended up passing on the round.
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Unread post10 Aug 2017, 03:59

Back when I was in Vietnam in 1967 as a Combat Engineer we used the M-14 while the Infantry used the M-16. It was more durable and less prone to jamming while running around in the mud and grass and the jungle. Granted it was heavier and more awkward to use but when we were given the chance to switch to the M-16 we chose to stay with the M-14.
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Unread post10 Aug 2017, 16:40

edpop wrote:It was more durable and less prone to jamming while running around in the mud and grass and the jungle.


A lot has changed in the past 50 years. The AR platform had the bugs worked out long ago & the current M14s in service (mostly in the DMR role) don't have a good reputation due to their complexity and poor reliability.
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