Very interesting.
Can anyone make a comparison of the performance of this 5.56mm 77 grain round vs a typical 6.8mm round?
The Next Infantry Assault rifle for the United States
- Thread starter Spetsznaz
- Start date
Can anyone make a comparison of the performance of this 5.56mm 77 grain round vs a typical 6.8mm round?
I haven't seen a straight up comparison, but the paper in the link I posted in my previous post talks about the ballistics of each round, and comes to the conclusion that the 6.8 would be the best... Everyone contributing to this post should read it, it talks about a lot of the issues that have been brought up here and in general...
There is no such thing as a perfect cartridge - there will always be trade-offs between weight, recoil, penetration, wound ballistics, cost, etc. The 5.56x45mm & AR-15/M-16 combination was adopted becuase at the time the elements within the US military had decided having full automatic capable service rifles was "the future", and the heavier 7.62x51mm had to much recoil to be easily controllable when fired from a full automatic rifle and resulted in a smaller basic load (which presumably the soldier would go through to fast using his rifle on full auto). This lead to the "spray & pray" of the Vietnam era. The USMC (and soon after US Army) sought a return to marksmanship in the 80's (with the advent of an all professional force having some influence on this decision no doubt) and fielded the M16A2 with its heavier barell & bullet, better sights, and the elimination of full-auto as a firing option (replaced by the little used 3-round burst). Well aimed single shots came back into style - arguably defeating the whole purpose of switching to the smaller caliber in the first place. Lets not foget that many of our NATO partners resisted the change over to 5.56mm and continued to field 7.62mm rifles (L1A1, G3, FAL, etc.) right through the 90's.
I've used the 5.5x45mm / M-4 combination in combat and it is an effective, highly mature system.
That being said, we can do better I think. The current operating enviornment is a combination of urban terrain and realtively open desert and arid mountains. For MOUT, a heavier bullet with better hard cover penetration would be useful. For open terrain, a more powerful round with longer effective range (paired with the now ubiquitous combat optic) would be very useful. There are also increasing reports of Taliban be encountered with body armor, and the US must assume that in any future conventional conflcit with a nation state it would be highly likley that US troops would encounter enemies with advanced body armor. In the past, the litmus test for penetration was a soviet steel helmet - in the future it will need to be level III body armor, in which case I don't want to be betting on 5.56mm from 14.5" barrel.
I would be happy to slightly reduce my basic load to get a more powerful round - especially in Afghanistan. Both the 6.8mm SPC and 6.5mm Grendel offer superior terminal wound ballistics from full sized rifles and shorter carbines as well as increased effective ranges over the 5.56x45mm cartridge, while at the same time offereing significantly reduced recoil from the 7.62x51mm cartridge, and they are both light enough not to seriously reduce a soldier's basic load compared to the 5.56x45mm.
The SCAR-L can be chambered for 6.8mm SPC. That, coupled with a TA31 ACOG and a Mk 13 Mod 0 40mm GL, would be my rifle of choice (if I had one - which I don't, so M-4 in 5.56mm it is).
SSG Gunn
Thank you for an informative post.
But globally we have adopted the 5.56 system. And a change, just for the USA alone, is gonna hundreds of millions.
I wouldn't spend the money because the new cartridge that only represents increased performance over the M855 does not justify raiding the already empty bank vault of the USA.
Not to mention explaining to your also cash-strapped NATO allies why the USA have - again - decided to change calibres.
Even if something that's significantly new and better comes along - like caseless - you may find that the armed forces anywhere is too broke to adopt it.
The 5.56 as a calibre isn't exactly harmless. If the M855 sucks, change the round, not the calibre.
Agreed. If we had never adopted the 5.56 system whole scale, we should indeed look for a better calibre.
But globally we have adopted the 5.56 system. And a change, just for the USA alone, is gonna hundreds of millions.
I wouldn't spend the money because the new cartridge that only represents increased performance over the M855 does not justify raiding the already empty bank vault of the USA.
Not to mention explaining to your also cash-strapped NATO allies why the USA have - again - decided to change calibres.
Even if something that's significantly new and better comes along - like caseless - you may find that the armed forces anywhere is too broke to adopt it.
The 5.56 as a calibre isn't exactly harmless. If the M855 sucks, change the round, not the calibre.
There is a different view on this emerging that justify this kind of expenditure of ammo. The Australians in Vietnam were pros - not conscripts. Yet, they, too, expended huge amounts of ammo per kill. And they wanted a fully-automatic rifle, period. I won't go into detail on that on this post about calibre.
And there is little doubt in my mind the 6.8 is better. The Brits and some other Europeans were about to adopt something similar before the US made everyone go for 7.62x51 NATO.
TheGrayMan214
New Member
77 gr round and tumbling of early 5.56 ammo
The tumbling pattern of the early 5.56's terminal ballistics is due to lighter bullet and 1:12" rifling in the early M16's and M16A1's. The 1:7" twist of the A2 and up came about in an effort to stabilize both the M855 62gr "Green Tip" round and the M856 64gr tracer in both the A2 rifle and the SAW. The new rounds had increased velocity. And were more stable. This doomed the round from "in the chest, out who knows where if at all" that early reports from Vietnam showed into the ice pick that we see today. Granted, a 5.56 at 3100fps through the brain housing group will result in someone who can't tell you that it's ineffective (the keys to winning a gunfight are NOT getting shot and shot placement anyway, regardless of caliber).
The Mk262Mod0 rounds are the 77 grain loads, and as far as I know, only SOCOM and those units with Mk18 SPR's are using them, but there again there could be more/less using it at the time b/c to be honest, haven't really followed it as I am part of a line unit and will most likely NEVER see an issued round of Mk262 in my M16A4's chamber.
My personal AR's see 75 grain loads all the time though... And I honestly think my Bushy perfers them over lighter loads (20" flat-top, 1:9" Chrome Moly w/ TA31H)
The tumbling pattern of the early 5.56's terminal ballistics is due to lighter bullet and 1:12" rifling in the early M16's and M16A1's. The 1:7" twist of the A2 and up came about in an effort to stabilize both the M855 62gr "Green Tip" round and the M856 64gr tracer in both the A2 rifle and the SAW. The new rounds had increased velocity. And were more stable. This doomed the round from "in the chest, out who knows where if at all" that early reports from Vietnam showed into the ice pick that we see today. Granted, a 5.56 at 3100fps through the brain housing group will result in someone who can't tell you that it's ineffective (the keys to winning a gunfight are NOT getting shot and shot placement anyway, regardless of caliber).
The Mk262Mod0 rounds are the 77 grain loads, and as far as I know, only SOCOM and those units with Mk18 SPR's are using them, but there again there could be more/less using it at the time b/c to be honest, haven't really followed it as I am part of a line unit and will most likely NEVER see an issued round of Mk262 in my M16A4's chamber.
My personal AR's see 75 grain loads all the time though... And I honestly think my Bushy perfers them over lighter loads (20" flat-top, 1:9" Chrome Moly w/ TA31H)
Last edited:
commander_matt
New Member
Once they get the 6.8 SPC round perfected, thats gonna be it. We should stay as far away from the 5.56 as we can after that. There are several manufacturers who are adding the 6.8mm to their platforms.
I think there should also be more research and experimenting done with the M14/M1A platform..
I think there should also be more research and experimenting done with the M14/M1A platform..
I don't think there is any need to replace the current weapons, for they are proven to work. I think small arms technology pretty much reached its zenith by the end of the Vietnam war (unless one day there are death rays or similar). You could take most late WWII small arms weapons and they would still be very effective today. These arguments just end up about which compromises are best, and there is not a real answer to that. Updating the weapons will just result in a different compromise, I don't see the point in that. Sure, make some incremental improvements as materials improve, but that's all they will be, incremental.
Todjaeger
Potstirrer
Just something to keep in mind about ammunition consumption by Australia and the US in Vietnam. The estimates I have come across suggested that ~50,000 rounds per kill were fired by the US. Australian troops were estimated to have fired ~300 rounds per kill by comparison.
From what I was reading (no, I do not remember the source at present...) The Australian command structure was rather unhappy about the high level of ammunition the troops were consuming, at least until they realised what the Americans were going through.
Something to keep in mind at least.
-Cheers
Those voices calling for 6.8mm now will be calling for something else after you've given them 6.8mm.
Why? Because the perfect solution simply doesn't exist. And you would have wasted hundreds of millions of dollars for a slight improvement. And any new thing would only reveal its faults after it is adopted en masse (and combat tested).
It's not as if in WW2 where full battle rounds were used, you didn't sometimes had to shoot some folks several times to put them down. How do I know?: From historical accounts many people survived gunshot wounds or kept fighting after being shot. There's no magic bullet - PERIOD.
So the guy didn't get stopped after one round, well shoot him several times more.
Why? Because the perfect solution simply doesn't exist. And you would have wasted hundreds of millions of dollars for a slight improvement. And any new thing would only reveal its faults after it is adopted en masse (and combat tested).
It's not as if in WW2 where full battle rounds were used, you didn't sometimes had to shoot some folks several times to put them down. How do I know?: From historical accounts many people survived gunshot wounds or kept fighting after being shot. There's no magic bullet - PERIOD.
So the guy didn't get stopped after one round, well shoot him several times more.
Last edited:
Yes, I read the same in a book about the 8RAR in Vietnam. The author did mention that the Americans may have factored in the ammo expended by their their AFV and air assets - especially the miniguns - not just infantrymen.
However, I seemed to remember a higher figure than 300 for the Australians.
But 300 rds per kill is still a lot of ammo. And remember, this figure was based on the 7.62 FN FAL. IIRC, the Aussie infantrymen carried only around 200 rds of 7.62 x 51. So you may have fired off your entire load of ammo and you still haven't killed one guy. Not unsurprising when you think of the jungle environment, night fighting and the fact that the unreligiously-motivated enemy usually did their best to avoid being shot.
It is incorrect to look at a few videos of the VN War and draw conclusions (not referring to you, of course). Even statistics must be examined closely. A C-130 firing miniguns from high up will probably use more ammo in one sortie than an infantry battalion use in a day. Did the VN US rds vs kill ratio statistics include these expenditure?
The troops in Vietnam weren't cowardly, bad marksmanship or plain bad attitude. The reality of the situation sort of demanded that kind of action. The jungle environment doesn't permit you to see the enemy (until he is at spitting distance). But by returning fire even when you can't see, you are discouraging the enemy from taking aggressive action to overrun you. And that's a good thing.
Last edited:
Todjaeger
Potstirrer
I am quite sure that the total included the mini-guns on the various CAS aircraft. If it was not including that, then the troops had some serious problems. Hernias come to mind for one thing, as 50k rounds of ammo, even if it is 'just' 5.56 x 45 mm, is not exactly light. Though the figure might have also included bombs, rockets, artillery shells and mortar bombs too.
What would be quite interested to find out, is what sort of kill ratio vs. ammunition expended did some of the smaller units like the LRRP and Force Recon units have? I have a sneaking suspicion that those figures would be somewhat better, even though they were primarily recon/intel units as opposed to direct action forces.
I also suspect part of the reason why US infantry units would have had such a high rate of ammunition consumption is because they way they were employed did not work particularly well in rough terrain against a guerilla force. A foot patrol conducted at the platoon level or high is not exactly what I would consider to a quiet force. This would have meant that any VC or NVA in the area would be aware of their approach and be able to either evade them, or setup an ambush that would be to their (the VC/NVA's) advantage. Anyway, we are getting somewhat far afield from the basic topic, that of the next rifle for the US.
My basic desire for such a rifle would be to have the weapon get back to having something like a 20 in. barrel, as opposed to the 14.5 in. barrel in the M4. It is that, or a totally new cartridge would need to be designed for optimal performance in terms of KE at muzzle, powder burn, accuracy, energy transferrence, etc from such a short barrel.
-Cheers
Defense Tech | The future of the Military, Law Enforcement and National Security
This link is to a good piece about the paper I posted the link to the other day...
Says the Army is now equipping each rifle squad with two M14s and squads are now using the Mk48 SAW, the 7.62 version....
However, the way I see it, they are still stubbornly refusing to go 7.62 across the whole squad, even though they've basically conceded it's better, and now they can potentially have logistics issues with multi caliber squads... I wish they would just "eat crow" so to speak, and give them all 7.62... Some people say it's overkill in urban areas, but I think it's better to have something that can work over all potential areas than having to switch weapons or parts of weapons for different missions.... A patrol isn't going to be in the mountains or on plains, approaching an urban environment, stop before they enter the city and switch out parts and calibers just because this one is only whats needed here or there.... If you are specifically going to one particular area, that's fine, but having one weapon / caliber combo that can work everywhere can cut down on logistics and mission prep time...
Get one caliber (not necessarily 7.62) that can work everywhere and leave it at that...
This link is to a good piece about the paper I posted the link to the other day...
Says the Army is now equipping each rifle squad with two M14s and squads are now using the Mk48 SAW, the 7.62 version....
However, the way I see it, they are still stubbornly refusing to go 7.62 across the whole squad, even though they've basically conceded it's better, and now they can potentially have logistics issues with multi caliber squads... I wish they would just "eat crow" so to speak, and give them all 7.62... Some people say it's overkill in urban areas, but I think it's better to have something that can work over all potential areas than having to switch weapons or parts of weapons for different missions.... A patrol isn't going to be in the mountains or on plains, approaching an urban environment, stop before they enter the city and switch out parts and calibers just because this one is only whats needed here or there.... If you are specifically going to one particular area, that's fine, but having one weapon / caliber combo that can work everywhere can cut down on logistics and mission prep time...
Get one caliber (not necessarily 7.62) that can work everywhere and leave it at that...
Last edited:
IMO, the attempt to standardise one ammo type within the squad was a "cold war" concept where nuclear fallout etc would make everything especially logistics difficult.
This concept had been proven a failure with the US switching quickly from one calibre to the other and still finding deficiency in both. No one rd will ever be able to do all the jobs in a squad.
But so far, I think most decent logistic department is is coping well with supplying different types of ammo with no problem. Armageddon hasn't happened.
Logistics had been supplying belted 7.62 to the GPMG, 5.56 belted and unbelted to the riflemen and SAW gunners, 9mm to the sidearms users, 40mm to the M203 gunner, rockets to the LAW gunner, hand grenades, mortar rds, 84mm RR rds etc to the infantry units for as long as I can remember.
So why should giving 7.62mm to the M14 Designated Marksmen suddenly create logistical problems?
Because now, you have two calibers to supply ammo for... If you only have one, you can either pack more of that ammo, or more of something else...
And as far as one round for all, why is a heavier round that works everywhere bad? The US military Heavy Machine gun, the venerable M2, is only chambered for one heavy round, but it's used everywhere, they don't switch it to a smaller round when entering an urban area, so why should issue rifles have to be changeable? I just don't see it...
My personal opinion, as a firearms instructor and someone who has studied wound ballistics and the myth of universal "stopping power" :
If they want to have interchangeable weapons parts and want to keep 5.56, have M16 20 inch barrel uppers and M4 14.5 inch barrel uppers in the arms room, that makes more sense to me than anything... Then the troops can be issued the M16 upper when going into longer distance engagement areas, becasue the 20 inch barrel keeps up the velocity and range for those distances, and if they are going into shorter distance areas, issue the M4 uppers, because they are more handy and the loss of velocity and range is not an issue...
Seems like the cheapest way to improve things to me...
If they want to have interchangeable weapons parts and want to keep 5.56, have M16 20 inch barrel uppers and M4 14.5 inch barrel uppers in the arms room, that makes more sense to me than anything... Then the troops can be issued the M16 upper when going into longer distance engagement areas, becasue the 20 inch barrel keeps up the velocity and range for those distances, and if they are going into shorter distance areas, issue the M4 uppers, because they are more handy and the loss of velocity and range is not an issue...
Seems like the cheapest way to improve things to me...
They haven't conceded it is better. They have just worked out that in certain environments, it is useful to have a longer range weapon (which just happens to be a 7.62 in the stockpile).
In Afghainstan, the enemy are using WWII era bolt action rifles because they are more accurate over longer distances. In certain circumnstances, they are better than modern assault rifles. Does that mean the army should go back to bolt action for most soldiers? Of course not. There are just different compromises and choices to be made for different environments, there is no "right" ammunition, or "right" gun, even among soldiers, there are different preferences depending on the individual. What has been learned, is the M16 is a very effective weapon with a nice balance of accuracy, firepower and weight, that suits a lot of people in a lot of environments, there has been no technological change that has effected that.
My opinion is formed from 2 years as a full time foot infantry conscript and 10 years as a reservist. What you described sounds like a luxury only special forces can afford.
At no point in 20th century history, were infantry units ever had just ONE calibre.
I have already detailed (a small fraction of) the different types of munition calibres a modern infantry unit is supplied with to fight. You have yet to explain why supplying 7.62 for DMR will suddenly make things difficult.
Are 7.62 hard to obtain? It does not exist in your inventories etc?
Honestly, can you really expect 1 shot 1 kill from anyone, regardless of round type in a real combat situation I know I'd be shaky and scared as fuck I'd be lucky to hit someone at 50m with a whole magazine, face it ammunition has almost been perfected, there is no way its going to get better (other than caseless etc but the same pysics etc will apply) only the experience of soldiers will lower shots to kill ratio's and even then the almost dependence displayed my modern armies on CAS, mortar and artillery etc. support will throw out these numbers.
- Thread Starter Thread Starter
- #60
To me its all about the art of handling a weapon, NOT THE DISTANCE! If you are one of those people who was just born to shoot, you can pick of a dude at 300m with a .22lr