For use in a general service individual weapon with, say, a 14 to 20inch bbl, can the 7.62x51mm cartridge be optimised further, or is the Mk319 Mod 0 approaching the limit of the design? While I see evidence of gun manufacturers optimising their weapons around the M80, and clearly the Mk319 series is an attempt to improve the cartridge’s relevance in the modern ‘general issue’ rifle, how much more slack is there in this aging design?
If a military user (who shies away from pushing the blurred constraints of the Hague Convention) was to opt for a 7.62x51mm general service cartridge instead of an incremental change (e.g. 6.8mm SPC) or a novel design (perhaps based on 7mm), is he limiting himself to early 19th century technology and the kind of terminal ballistics that will vary little from the original 30-06?
No agenda, just trying to work out whether the 7.62mm has a future or if it’s hit its peak as a design.
Yeah, it definately has a future. Used by every NATO country and many more. Easily found but moderately costly to run in volume. In it’s hotter civilian designation it’s the 6th most popular sporting cartridge in the USA. Like it’s much older IR/FSU/Warsaw Pact competitor it will probably be with us for quite some time.
I have heard from many unrelated sources that it’s 7mm offspring is the best, but have no personal experience.
I do understand what you mean with your sentiment. It has really surprised me that there have been no MAJOR advancements in cartridge development for 40+ years, mearly small steps.
While I see evidence of gun manufacturers optimising their weapons around the M80, and clearly the Mk319 series is an attempt to improve the cartridge’s relevance in the modern ‘general issue’ rifle, how much more slack is there in this aging design?
7.62x51 is not any different from any other center fire cartridge introduced in the last 100+ years. The only difference is in the physical dimension of the case. A cartridge that is introduced today is basically the same as any other from any point in time.
You could say the metallic cartridge in general is an aging design and right now there is nothing that is going to replace it. I would call the metallic cartridge ‘state of the art’ design.
I agree. Until we discover another projectile material, or another propellant with more efficient characteristics, we are just making little tweaks here and there. Now that we have projectiles that expand to any size we want (2" or so expansion from a .45, for example), we are balancing expansion/penetration (1"/12" from a .45 HST), and there isn’t much left to do, the way I see it.
7.62x51mm is a lot of things, but aging it is not. If I knew for certain I was going to be in harms way on a given day and had the luxury of preparing for the encounter in a relatively static position, I would much rather be shooting a .308 with good ammunition than 5.45x39 mm, 5.56 mm, 6.5 mm, 6.8 mm, or 7.62x39 mm, as the .308 has the greatest likelihood of rapidly incapacitating an opponent over a wide variety of circumstances and potential engagement scenarios, as well as being much better at penetrating intermediate barriers and shooting into vehicles than the common assault rifle calibers. In fact, .308 is probably the best general purpose cartridge available; if I was limited to one rifle caliber, then .308 would be it, as it capable of shooting from up close all the way out to 1000 depending upon equipment and shooter limitations. It can handle all game in the lower 48 states with wise load selection, as it works with projectiles from 110 gr to 180 gr–fragmenting, barrier blind, as well as good hunting and match loads. The only downside is the additional weapon and ammo weight, bulk, and cost compared to assault rifle calibers.
In fact, .308 is probably the best general purpose cartridge available.
I would have to agree with that statement. But I could also say the same about any of the rimless, full power service cartridges of all nations in the past 100 or so years. The cartridges developed for the bolt action military rifles were designed to produce the maximum power that the average infantryman could comfortably handle in a 8 to 10 pound manually operated rifle. Although it was technically feasable at that time, they did not develop a 7.62x39 or a 5.56x45 type of cartridge for their bolt actions. At the time, advocating such cartridges would have been laughed at. I know that I wouldn’t have wanted a 5.56x45 1903 Springfield rifle. Such a rifle sounds absurd, to me at least.
The 7.62x51 is within the power range of the 20th Century battle rifle cartridges. The 7 or 8mm Mauser, French 7.5, Swiss 7.5 and similar cartridges could have been as effective as as the 7.62x51 but they were not the cartridge that was adopted by NATO.
With the 7.62x51, the big mistake was thinking that a cartridge, in that power range, could be controlled during full automatic fire from a light weight rifle. That is why we eventually went to reduced power cartridges for the current select fire assault rifles.
Any rimless, full power military rifle cartridge in the aprox 2500 ft lb power range, is ideal in a properly designed bolt or semi auto battle rifle. The debatable quest for full auto capability in the infantry rifle, is what sapped the power from current military rifle cartridges.
I hear you, and you hit the nail on the head with the caveat: ‘with good ammunition’.
My concern is this. For most western militaries outside the US, the habits, misconceptions and inertia of procurement agencies mean that a 7.62x51mm capability will most likely be based on the M80 cartridge. The only other rounds they’re likely to buy will be tracer, dim tracer, AP and maybe a long range round. They’ll think all their terminal effect issues will vanish because they’ve rushed back to the safe and powerful busom of 7.62mm, but want the same terminal ballistics from a carbine length barrel at 100m as from an MG barrel at 600m+ .
they also won’t want to spend the money on training recruits and soldiers how to wield a 7.62mm weapon (even if they buy a GS rifle with a decent length barrel).
That to me sounds like a pretty out of date way of doing business, so maybe the ‘aging’ is more obvious in the way people chose to approach the Hague convention and how they develop a capability. I’m concerned that for various intransigent Big Army reasons, an organisation would be stuck with the M80 if it went 7.62x51mm and in some weapons, that’s a turd you cannot polish.
I agree with the posts that .308 is possibly the most versatile cartridge around. .30 caliber in general is extremely popular and the choice (and price) of bullets is astounding. You can load up 110gr bullets for varmints on the low end, use the
“middleweight” 150-175gr bullets for SD/duty loads, 180-200gr bullets for large game, and my personal favorite, the 208gr A-Max for long range. You can find factory loads in virtually every bullet weight and if you handload you have a huge variety of powders available and components are quite common.
I’m concerned that for various intransigent Big Army reasons, an organisation would be stuck with the M80 if it went 7.62x51mm and in some weapons, that’s a turd you cannot polish.
Now M80 is a turd? That’s a new one on me.
I guess that the similar .30 M2 Ball, the US service cartridge of 2 major wars, is a turd too?
“Now M80 is a turd? That’s a new one on me. I guess that the similar .30 M2 Ball, the US service cartridge of 2 major wars, is a turd too?”
M80 is reasonable for use as linked MG ammo–although M59 is better in this role, but M80 is less than ideal for use in rifles and carbines. Currently there are numerous other loads being used that offer much better terminal performance than M80 ball, especially out of shorter barrel carbines. You should speak with Pat Rogers how he felt having to shoot NVA multiple times at close range with an M14 using ball ammo in order to try to get them to stop their hostile actions…
As noted in previous threads, the JSWB-IPT discovered that Lake City has manufactured TWO distinct types of M80 FMJ over the last several decades, one using a thick copper jacket that does not fragment, as tested by Dr. Fackler at LAIR and another previously untested version using a steel jacket that fragments at velocities above approximately 2800 f/s. Yaw and fragmentation occurs at about the same penetration depth as with copper jacket M80, and is thus deeper than ideal (ie. NL too deep). When the velocity drops to below 2800 f/s (by approx 100 m from 22" barrel M14), M80 steel jacketed bullets no longer fragment and instead act like the non-fragmenting copper jacketed M80 FMJ.
Note that LC does NOT distinctly label the different M80 FMJ projectiles and the only way to tell them apart is to use a magnet. There is a wound profile showing the different terminal performance of M80 ball on page 21 of an NDIA briefing I gave–contrast the M80 ball terminal performance with that of the 155 gr TSWG loading noted on page 22…
Not in all applications by any means, but in some of the personal weapons that are in vogue now in militaries? Yes, absolutely. The drive towards lightweight, compact weapons with low training burdens may be admirable, but the sum of those three factors is not necessarily an effective battlefield implement. The M80 (in either jacket configuration) is not excellent in short barrelled weapons, and I would not want to go against first or high-second order militaries with such a system.
And I’m not slating the M2. As part of a battlefield system that included: a) troops trained in marksmanship and the correct application of collective fire, and b) the M1, BAR and M1919 MG, it was a battle winner; as demonstrated by all those battles you guys won.
The thing is, we no longer give 17-18 year old male and female recruits a 24 inch barrelled semi-automatic weapon as their primary weapon and tell them to engage the enemy as they choose at a range that optimises the performance of their weapons. Instead they have to engage him at 20m as they exit a vehicle, and then again that night at 600m as they’re pulling sangar duty. All with a weapon some desk-bound committee selected because it weighed less than some arbitary weight and is shorter than the sandwich they had for lunch.
In such a reality, I think we’re right to try and seek out the best possible cartridge, rather than rely on one that won a war in a completely different weapon (under completely different circumstances) before the advent of general issue body armour and pop up bad guys.
The identification of the 2 jacket types was a really useful (and illustrative) example of why manufacturing changes should be scrutinised in “simple” large volume small arms rounds (‘simple’ is the general perception, not the reality). Plus, it demonstrated (again) why fragmentation should not be seized upon as the untimate solution to terminal effect concerns. Unless it’s repeatable at the necessary engagement ranges from the barrel of the IN SERVICE weapon (not a test barrel), it’s a phenomenon unlikely to be seen regularly in combat.
Do you perhaps know the velocity threshold for fragmentation of this thin steel jackect M80?
M80 ball has about 2800 fps muzzle velocity out of a 22" barrel, but is down to 2680 fps at 50 yds, and 2564 fps at 100. Shorter barrels (17.7") in weapons such as a G3 or Para FAL have about 2660 fps muzzle velocity, so perhaps they are nearly out of the fragmentation range even at point blank.
Most (all?) euro countries that manufactured similar thin steel jacket 7.62 NATO loads in the past have intentionally changed them to avoid this fragmentation effect, since it is not politically correct. The swiss even designed their 5.56 ammo to avoid fragmentation…
As noted above, fragmentation threshold of the steel jacketed M80 FMJ is about 2800 fps. Ave MV of the M80 ball we have tested has been about 2850 fps out of 22" barrel M14’s.
Anyone know the fragmentation threshold of Hornady 155 gr. AMAX and Nosler Ballistic Tips?
I’m guessing, if short barreled 7.62x51mm Battle Rifles shoot below the fragmentation envelope, in general, one is better off choosing expanding barrier-blind ammo such as Barnes-X?