New American rifle 7.62x51mm

[The Basket]

Also mentioned is the M16 direct impingement gas system.
They want either short stroke or long stroke gas piston.
I get the feels that the M-16 was never truly loved and most of the changes are simply a stick to beat it with. Replacing the M-16 with another 5.56 is silly but it can be replaced with a 7.62 which can do things the M-16 can demonstrably not do.

 

[parsifal]

One thing to remember is that wounding a man in a western style army is probably more detrimental to unit efficiency and costly than killing him outright. It generally takes anywhere from 6-10 guys to triage, and then evac the injured soldier. If the casualty needs to be airlifted there is a risk of losing that helo, and in any event is using that asset when it might be needed for some other task as well. Losing a man outright is detrimental to unit morale and leaves a gap in squad capability, but at least few or no resources are used to further treat that man.

Moreover, depending on the standards that apply to casualty classification, it might be years, if ever before that man can return to service. My stepfather fought at Stalingrad, but was wounded by a sniper before the encirclement. He was shot in the arm, not that badly in his words (though he was decorated for his trouble). Despite this he did not return to service until June 1944, after the emergency in the west became apparent. Even so he was rapidly press ganged into the new 6A and shipped off to Rumania and finished up in Hungary (or possibly Austria….Im unsure). Point is though, that snipers bullet put him out of action completely for more than a year, and even after he returned to service he could not carry a rifle. He was essentially "walking wounded", press ganged back into support echelons as Germany went through the most acute of manpower shortages.

From a resource management point of view, it was more costly to wound my step father over killing him. Im glad that he was not killed incidentally.

A 5.56mm shell is purported to be less lethal than a 7.62mm round. Ive yet to be convinced of that, but if true, its probably a more effective weapon than the 7.62mm round from the point of view of curtailing operational efficiency, but only against an enemy that cares about its soldiers and its wounded. Against an army of madmen, intent on killing itself and fighting to the death, usually involving some form of self immolation like blowing themselves up, the shoot to wound strategy simply falls apart. In that scenario, you need a first round kill at maximum range, on a scale within the force structure. That's where the emphasis on shooting accuracy over shooting volume comes into its own, and might be some of the reason our guys have been judged the most efficient units by the (I think) US military for nearly every year of deployment since 2001.

 

[Shortround6]

The M-16 saga was a comedy of errors in the beginning which established a bad reputation that took decades to overcome. If then,
was it the rifles fault the army failed to issue cleaning kits or cleaning rods? Which genius told the troops it was self-cleaning? The last minute powder switch and so on.

Yes it had a few mechanical faults but not as many as some people believe.

The Army is in the same position it was in the early 30s with the M1 rifle. Too many 5.56 rounds and too many 7.62 rounds in stock to change to a cartridge that will offer any improvement over either. So any new rifle is crippled in one way or another. In fact many new rifle rifle requirements are hampered by the need to use existing magazines.

7.62 ammo is large and heavy limiting the number that can be carried, in has too much recoil to make a full auto gun even remotely practical. It is less practical in short barrels than a cartridge with a lower powder capacity due to flash and blast.

yes it out ranges the 5.56 but after that it's attributes tend to fade. It is used because it is the only alternative in the supply system.

 

[Torch]

Besides the weight of 7.62 rounds the Scar 17 is actually a very soft shooting rifle....

 

[Token]

The term "Designated Marksmen" may be new but any outfit that had seen much combat probably had a few natural leaders (regardless of actual rank) or "go to " guys the officers relied on. Trouble in green outfits was the officers didn't know which troops to trust and the troops didn't know which officers/non-coms to trust.

Performance on the range is not a guarantee of performance in combat except in the negative. Troops that can't shoot on the range will NOT miraculously become good shots in combat. Someone who posts good scores on the range may or may not freeze in combat or otherwise perform sub par.

Yeah, but in a Designated Marksmen we are not necessarily talking about leaders, we are talking about designated riflemen at the squad level who take deliberate aimed fire even when the rest of the unit is laying down suppressing fire. To the point they are sometimes equipped with rifles that are not full auto capable.


Naturally, some of the attributes that will make a good Designated Marksmen will also be attributes that cause him/her to rise to the top of a unit in combat, so they well may be leaders within the unit, regardless of rank.


But the equipment portion was actually what I was talking about, in particular to your comment about over and under buying. The Designated Marksmen often requires different equipment to be most effective.


With regards to freezing or not, I think training has reduced that propensity quite a bit in many major military's today. For example, more realistic, stress centered, training, vs simple range days. Training techniques that used to be only the realm of elite units are more often used at the average unit level today. Of course, there is still a long way to go in this aspect.


T!

 

[soulezoo]

The genesis of this change (what's old is new again) has to do with the concept of "overreach" on the battlefield. Basically put, the weapons of the enemy has a greater reach or lethality range than our weapons do. For instance, we use for a squad automatic weapon a M249 in 5.56 mm. The enemy, basically using Russian weapons use a PKM firing the 7.62 x 54R has a much greater range. Now we can counter with the M240 in 7.62 x 51, but we don't use that in the same numbers they do the PKM.

SR6 already hit on a few salient points, but allow me to add a few more.

First, we are always fighting the last war... the discussions here have even bordered on that and the opinions reflect it. Politics and logistics prevent us from getting what is really needed. IMO, the cartridges needed exist and the rifles exist. The need to marry the two and then procure is what holds us back.

The SCAR is a fine weapon and an evolutionary leap from the FAL and the G3. It is in use in some Spec Ops today. It is a heavy beast though and troops of today (don't forget women) have a hard time carrying all that crap around. I'll tell you, after 25-30 lbs of body armor, another 25lbs of gear then 10-11lbs of rifle with associated ammo, I got damned tired at the end of the day and I'm not a small guy. Heavier guns and ammo is not a blessing! Ounces make pounds and pounds make pain! (Full disclosure, I have a FAL, a number of M-4's, HK91, and significant trigger time behind the SCAR 17)

Item of note: Russia has mostly abandoned the 7.62x39 and its troops use an AK-74 variant for the most part firing a 5.45mm projectile.
I made note of some of the accuracy questions. That accuracy has as much to do with the projectile and ammo as it does the rifle. An AK-47 is notoriously inaccurate due to poor ammo and the nature of the rifle itself and loose tolerances. An M-4 with a good match barrel can shoot Mk 262 ammo sub MOA all day long. Feed it some M855 and the groups open up to 2-2.5" at 100 yards. That's the best that projectile will do. (Steel core projectile designed to penetrate Soviet helmets at a given distance).

The HK 416, 417 while fine weapons are not the be all end all. Short stroke piston weapons have a different recoil feel to them that somewhat degrades accuracy for precision shooting. But it improves upon weapon fouling and does not heat up the bolt and receiver the way DI does.

Any of these battlefield cartridges from 7.62 x 54R on down suffer significant lethality degradation at range. The bullet will get there but not a lot of ass behind it when it does get there (600+ meters). Enough to wound certainly. Perhaps not enough penetration to kill though unless a fortuitous placement is made. Closer in, dead is dead. I've seen 5.56 M193 rounds literally rip a guys leg off at 50 yards. I've seen the same simply punch a couple of very small through and through holes and the victim barely knew he was shot at 200 yards.

Any cartridge adopted will be a compromise of one thing or another. Weight vs power vs recoil vs range and etc.

For an intermediate cartridge that will fit in current weapons, I kind of like where the 6.5 Grendel was going. I'd like to see just a little bigger case for about 2-300 fps faster. But even as is, it is a 1000 yard round in a 22" barrel. And does not recoil much more than 5.56. Weight is somewhere between 5.56 and 7.62.

 

[Shortround6]

Disclosure, the forum name is from a short 6.5mm round I had built a number of years ago. The Rem Benchrest case. Roughly a .308 with a 1/2in taken out of the body and 30 degree shoulder.
Too short and fat to make a good automatic weapons cartridge but the powder capacity is pretty much close to what is needed.
30.5 grains of 4895 (hardly an esoteric powder) gave about 2600fps to a Serria 120 Matchking from a 26in barrel.
which pretty much matched the ballistics of a 7.62 X 51 firing a 168-172 grain bullet.

Perhaps it could be loaded hotter, I have no idea. It shot good (scary actually) and I had the 6.5 X 308 (full length ) for long range (over 300yds) . Either 2900+ fps with the 120 grain bullet or 2600-2700fps with a 140 from the larger case without pushing things.
The 140 grain bullet would pretty much match a 190 grain .30 cal match bullet.

I didn't really try the really pointy 107, 123 and 142 grain bullets. The short round had a 1 in 10 twist barrel and wouldn't shoot 140 grain bullets with the powder charge I tried. Perhaps loaded hotter with a different powder?
Long case gun used a 1 in 9 twist and 140s stayed stabilized at 1000 yds the only time I tried that range.

6.5 ammo is going be quite a bit heavier than 5.56 but lighter than 7.62 but has about zero chance of being adopted due to stock piles of exiting ammo and NATO standardization.

 

[DerAdlerIstGelandet]

I personally found the 5.56 easy to learn and shoot with. It may not be the best combat rifle today, but the M-16 and it's variants are easy to give to a young kid off the block who has never fired a rifle and quickly turn them into a marksman. It has very little recoil, and reliable. Easy to take apart, clean and maintain. Easy to clear jams, and light weight.

I still enjoy shooting the weapon, and own a 5.56 mm AR-15 in the M-4 Carbine variation with a red dot/night vision scope/sight. Easy and fun to shoot. Accurate and very, very little recoil.

 

[The Basket]

If the American do go 7.62 then does NATO go 7.62?

 

[parsifal]

This article might be useful, though I haven't read it properly

7.62 mm Versus 5.56 mm - Does NATO Really Need Two Standard

 

[soulezoo]

That is an issue paper from the 80's. It is interesting to note that while projectile improvements to the 5.56 is touted as making the round more effective (to be fair, this article is supportive of 7.62 and dismissive of 5.56), none have thought to make the same improvements to the 7.62 projectile.

IMO, the SS109 62 grain steel core bullet is a lousy projectile that does nothing well. Except maybe to penetrate Soviet helmets at 1000 yards. That's if one can come any where close to where one is aiming.

US Special Forces played with the 6.8 SPC for awhile. This cartridge was developed to improve lethality at closer ranges. Experience in the CQB environment exposed the limitations of 5.56 and led to this change. The 6.8 worked well under 200 meters. However, lower muzzle velocity meant that effectively the 6.8 was done around 400-500 meters tops.

 

[Shortround6]

It wasn't just the velocity, although that was part of it.

The problem was trying to use standard 5.56 length magazines (easy conversion of old rifles, new barrel, new bolt and new magazine fitting in old magazine well) which mean that they had to use a short bullet of not very good ballistic shape to keep the overall length down without shoving the bullet back into the case and cutting down on powder space which would have further affected the velocity.
A longer bullet of similar weight (more pointy on both ends) and just a tad more powder space would have offered a lot more range but would not have fit the exiting rifles for refit.

 

[The Basket]

Fighting the last war is problematic as you could learn the wrong lesson.
Siege of Plevna? Still relevant today even if that battle was 1877! Long range gun for long range. Short range gun for short range. Simples.
The main issues are body armour and fighting insurgents who have suicide vests and the rifle that is needed in this war.
A modular weapon where you can change the barrel and the calibre would make sense.

 

[Reegor]

I recommend the following book to anyone interested in this thread. It traces both the hardware (the standard infantry rifle of each period, for example) and the doctrines that went with them. One of the author's arguments is that there has always been a tension between the "accuracy" doctrine and the "firepower" (saturate the enemy with poorly aimed rounds) doctrine. According to him, the firepower doctrine tended to win consistently in the US military.
He discusses issues like caliber, value of smokeless powder, etc. at length. I think the book ends before electronic sights became common.
Enjoy! This is way outside my own area, but I wrote a book on firearms manufacturing from 1800 to 1980, and this was part of my research for the book.

 

[Clave]

If you want to kill people a long way away, bring back the Lee-Enfield .303

 

[Clayton Magnet]

The problem was trying to use standard 5.56 length magazines (easy conversion of old rifles, new barrel, new bolt and new magazine fitting in old magazine well) which mean that they had to use a short bullet of not very good ballistic shape to keep the overall length down without shoving the bullet back into the case and cutting down on powder space which would have further affected the velocity.

Hence the creation of the .300 Blackout. fires a 7.62mm projectile from a 5.56mm case, uses the same magazines and bolts as the 5.56 NATO, just requires a new barrel.

 

[Shortround6]

Could have the same problem, either a short poorly shaped projectile to preserve powder space or a long streamline bullet that is deeply seated and doesn't really have enough powder space to do the job?

 

[soulezoo]

The Blackout is good for one thing and one thing only. Subsonic suppressed shots at short distances. Anything else, and the round is outclassed by dozens of other cartridges and rendered nearly meaningless save for the aforementioned ability to only have to swap a barrel to use.

 

[Shortround6]

It seems to have the same (or roughly) ballistic capability (or potential) as the 7.62 X 39 so while we may argue about that capability it is rather obvious that it will never be a dual role cartridge (close in infantry rifle/carbine and support/armoured fighting vehicle machine gun)

 

[Clayton Magnet]

I suppose then perhaps the US shouldn't have been so dismissive of the .280 British adoption. If the US does abandon the 5.56 (Doubt it, at least in the next few decades) I for one will do my part, and gladly take a few crates of surplussed ammo to feed my AR. Assuming of course, that Canada's present government does not reclassify it as prohibited, but that is an argument for a different thread.