Section Infantry Weapons

Contains threads on British Army equipment of the past, present and future.
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ArmChairCivvy
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Re: Section infantry weapons

Post by ArmChairCivvy »

jimthelad wrote:The vehicle and helo mounted systems are already powered up
The RM should have done with this (the distances in engagements in mountaineous terrain can be extra-long!) instead/ in addition to putting mortars on the back
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Re: Section infantry weapons

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They did with Milan in the 90's. I wouldn't want to be the mortar crew, the back blast would barbeque them. Besides, you want your mortar systems 2-3 km behind FLOT to best use the propellant/angle variance benefits of time on target barrage.

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Re: Section infantry weapons

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Anyone with any knowledge and background of the new US army 6.8mm round, have only recently seen mention of the 6.8mm TVCM polymer cased round, understand one of several 6.8mm rounds the US Army will be testing, 170,000 6.8mm TVCM rounds delivered.

First impression of the 6.8mm TVCM looks like a more powerful version of the original British 280/30 - 7x43, of the late 1940's. An intermediate round with its recoil energy limited so as to be controllable when fired in fully automatic mode from an assault rifle. The assault rifle was a development of the of German MP43/44/Stg44 designed to put firepower in the hands of the German troops to stop them being overwhelmed in countering the much larger numbers of Soviet troops on the Eastern Front.

The German assault rifles used the 7.92×33mm Kurz (short) round a cut down version of the standard German Army 7.92×57mm cartridge, so as to be controllable when fired in fully automatic mode.

The new 6.8mm looks like it might be too powerful to be controlled in fully auto firing mode, might be wrong, why looking for specs, weight of bullet, recoil energy etc

PS The 280/30 was designed to used in the EM-2 assault rifle and the TADEN light machine gun.

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Re: Section infantry weapons

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NickC wrote:The assault rifle was a development of the of German MP43/44/Stg44 designed to put firepower in the hands of the German troops to stop them being overwhelmed in countering the much larger numbers of Soviet troops
MGs were always crew-served weapons in the German army and paratroopers, jumping individually, did not have assurance that A. the crew member, and B. the MG and a plentiful supply of rounds would land near to each other
... hence a weapon that could so both a rifle and (partially) an MG job was designed, initially for them

Kalashnikov powered that round down... and the rest is history
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Re: Section infantry weapons

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ArmChairCivvy wrote:
NickC wrote:The assault rifle was a development of the of German MP43/44/Stg44 designed to put firepower in the hands of the German troops to stop them being overwhelmed in countering the much larger numbers of Soviet troops
MGs were always crew-served weapons in the German army and paratroopers, jumping individually, did not have assurance that A. the crew member, and B. the MG and a plentiful supply of rounds would land near to each other
... hence a weapon that could so both a rifle and (partially) an MG job was designed, initially for them

Kalashnikov powered that round down... and the rest is history

No expert in military small arms but the Kalashnikov looks like their take off of the German MP43/44/Stg44, the British EM-2 was slightly more nuanced in that the 280/30 - 7mm x 43 round had a better BC and so longer range than the Soviet AK47 round 7.62 x 39 (actual bullet dia.7.9mm and both the German 7.92 Kurz and the 7.62 Russian both designed to make use of current production facilities used in production of their full power rounds).

Back to the future, the aim with the British 280/30 -7mm x 43 round was so infantry section needed only one round, not two as currently with the 5.56mm and 7.62mm and googling revealed that is the same thinking that is driving development of the new US Army 6.8mm round to replace both 5.56mm and 7.62mm. (Churchill cancelled the 280/30 in 1951 after winning general election to standardise on the US 7.62mm)

The US Army insisting on even better ballistics with the new 6.8mm than the 7mm x 43, talk of 3,000 fps second from a 16" barrel, that means more powder and very high pressures required of ~90,000 lbs mentioned, which guaranteed to be barrel burners even with stainless steel due to the heat generated especially with bursts at 500 to 750 rpm.

So unless US Army have a barrel made of new and expensive unobtainium material think 6.8mm doomed to failure.

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Re: Section infantry weapons

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NickC wrote:both the German 7.92 Kurz and the 7.62 Russian both designed to make use of current production facilities used in production of their full power rounds
Necessity, especially in wartime, is the mother of all invention... if need be, to be perfected later.
NickC wrote:5.56mm and 7.62mm and googling revealed that is the same thinking that is driving development of the new US Army 6.8mm round to replace both 5.56mm and 7.62mm
The Swedes must be tearing their tunics as they had that uniformity, but as production of rounds was so expensive to maintain for peace-time volumes, they went with NATO calibers
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Re: Section infantry weapons

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This thread was treading over the same ground in the summer of 2017, just to try to keep it short as a rehash, and of course what the US competition would bring to fore was not known at the time:
ArmChairCivvy wrote:Given the impossibility of extending the effective military
range of the .223 Remington to 600
m..." This became history [in the sense that the French gave up on a new round in mid-70s and stuck with the ones in service]

But what the US Army is doing they are creating space in the magwell, and then the new intermediate round can be converted to at will
- Lapua 144 grain grendel retains 911 lb ft at 400 mtrs (and that is done within the limitation of existing magwells) vs the 549 quoted at the top [calculations by Little J], for 500 yards
- and is very close to the French [abandoned] target of 647 at 600 mtrs (637, when the normal grendel is already down to 460)
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Re: Section infantry weapons

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At least the UK has an interest in the US Army programme though no commitment beyond that. The UK is happy to use the 5.56mm out to 600m and train for that as the SA80 is accurate out to that range, one of the reasons the LMG was ditched. Therefore we will keep probably keep using the L85A3 until they are totally worn out or NATO changes its standard ammunition type, whichever happens first.

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Re: Section infantry weapons

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Lord Jim wrote:use the 5.56mm out to 600m
I won't go to the accuracy (as for what the average infantryman can be trained to hit at 600m), but have you given any thought to terminal performance?
- something of a driver, if you read e.g. what Gnrl Milley has said around the latest efforts

The "latest" was well on the way bfr A-stan gave impetus to 7.62s being handed out en mass, to look after those that only had been given pea shooters
- I am (of course) exaggerating just to ram the msg home; horses for courses etc

So, working backwards from the terminal performance of your favourite round ( and this shows why I am not concerned, as NickC is, about the barrels wearing out; rather, as a shooter I would be concerned about the rifle blowing up my face, were the 5.56 asked to do things that it simply can't):
Muzzle velocity is constrained by the interior ballistic constraints and considerations: there are limitations on chamber pressure and charge mass.
- brings to mind that it is often uttered that the British Army is using the heavist bulpup around, but working out why that might be is not so obvious

Using the M855 as a worked example, it attains nearly the maximum allowable [ for the lighter M-16, SF's favourite and all that] chamber pressure during the interior ballistic cycle.
- if heavier variants of the M855 are fired with the existing charge, the maximum allowable chamber pressure would be exceeded resulting in possible catastrophic failure of the gun tube. The result is that lower charge weights must be utilized for heavier bullets so that the maximum allowable chamber pressure is not exceeded. This typically produces lower muzzle velocity as the projectile mass is increased.

Additionally, for the M855, the volume available for propellant is nearly completely occupied by the current propellant load and it is difficult to add additional propellant to increase the current muzzle velocity of the round.
- is particularly a problem for lighter bullets that could be used as a work-around and fired with increased charge masses without exceeding the maximum chamber pressure. For lighter variants of the M855, the maximum charge volume becomes the constraint limiting muzzle velocity rather than the maximum allowable chamber pressure.
- by way of comparison, it is handling this chamber pressure on the US Army's 50+ km field gun that has held back its err, fielding (though the 'official' story is competing for funding with other hi-prio projects)

We have seen constant and respectable improvements of the 5.56 over decades... but the economist in me would say diminished marginal returns (for any further effort) have already set in
- what would you say?
- and I hope Little J will jump in (with his remarkable collection of ballistic computational aids :thumbup: )
Ever-lasting truths: Multi-year budgets/ planning by necessity have to address the painful questions; more often than not the Either-Or prevails over Both-And.
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Re: Section infantry weapons

Post by Lord Jim »

The M855 (SS109) is no longer used in most units in the US Military since 2010 when it was replaced in US service by the much improved M855A1(EPR) that will reliably shoot 8x8 inch groupings at 600m, and has superior ballistic and penetrative performance to the M80 7.62mm round.

The UK used its SS109 round called the L15A1 until it was replaced by a new round called the L31A1 which is optimised for long range penetration rather than fragmentation out to 600m.

The big advantage the L85A3 brings over the M4 and its relatives is the barrels that is at least 6 inches longer ( 20 inches vs 14.5 inches) and that makes a real difference in velocity. As for hitting the Target, British front line troops are issues with the Elcan Spectre OS4x, often fitted with a Doctor Red Dot on top for CQB engagements. This greatly enhances the already impressive accuracy of the L85 and combined with the marksmanship of the British Infantryperson makes accurate engagements at 600m with a 5.55mm consistently achievable.

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Re: Section infantry weapons

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Lord Jim wrote:(EPR) that will reliably shoot 8x8 inch groupings at 600m, and has superior ballistic and penetrative performance to the M80 7.62mm round.
ArmChairCivvy wrote:would say diminished marginal returns (for any further effort) have already set in
These not the exact words but still pretty much what Gnrl Milley said about bringing the EPR into service = end of the line

I don't have the stats at 600m of EPR vs. the various incarnations of Grendel - the best retained energy award so far has been going to the Lapua design.

However, someone, after much sole searching, has decided that the first quote (for performance) is not good enough.
- France has made a move, Germany has made a move (both felt they had to)
- we are waiting for the US to see what happens by the time the latest UK upgrade will be due for replacement; a fun game to watch (save for the glacial speed that anything moves)
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Re: Section infantry weapons

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Problem with M855 A1 (and its like) is that the barrel pressures have gone up so high that your safety margin to the proof load is almost halved...

https://www.thefirearmblog.com/blog/202 ... s-6mm-arc/
The new 6mm ARC round has promise (and is extremely similar to an idea i had years ago :D ), the new 6.8 round the Yanks are working on appears to be aimed at a space between the 556 and 762, but not necessarily designed to replace either.

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Re: Section infantry weapons

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Little J wrote: aimed at a space between the 556 and 762, but not necessarily designed to replace either
So you don't see a unitary (as for ammo carried) squad coming?
Ever-lasting truths: Multi-year budgets/ planning by necessity have to address the painful questions; more often than not the Either-Or prevails over Both-And.
If everyone is thinking the same, then someone is not thinking (attributed to Patton)

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Re: Section infantry weapons

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As for this
"The 6mm ARC delivers substantially better ballistics than the 5.56 NATO with similar recoil and yet delivers comparable ballistics to the venerable 308 Winchester with 30% less weight on both weapons system and ammunition."
Sako (owned by Beretta) is just coming out with a DMR (semi-auto) and a bolt-action version of the same rifle, both using the 308 Winchester
- the DMR moving with his section (but with unique ammo)
- and the sniper(s) assigned from higher unit level down to where ever they are needed... now having some commonality with the guys he/they will land with (as opposed to the higher performance/ ranged, but unique-to-snipers ammo)

Compromises, compromises?
- any comparisons for the ARC vs. Grendel?
Ever-lasting truths: Multi-year budgets/ planning by necessity have to address the painful questions; more often than not the Either-Or prevails over Both-And.
If everyone is thinking the same, then someone is not thinking (attributed to Patton)

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Re: Section infantry weapons

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ArmChairCivvy wrote:
Little J wrote: aimed at a space between the 556 and 762, but not necessarily designed to replace either
So you don't see a unitary (as for ammo carried) squad coming?
556 isn't going away for a long, long time, the new 6.8 is all about "overmatch" at the expense of lower powered situations, i.e. room clearing. I will concede that it will probably replace 762 (if the Yanks actually follow through with it this time), but even that will take time.

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Re: Section infantry weapons

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Little J wrote: lower powered situations, i.e. room clearing
If in doubt, use a lot of hand grenades.
- and if not :) in doubt, punch thru the wall with support weapons?

Security forces tend to have a wide selection of weapons (hi-power shotguns to deal with doors/ locks, ammo that does not ricochet etc) which they choose for the occasion
- front line combat troops will have to come to the party as they are (regardless of what the occasion turns out to be)
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If everyone is thinking the same, then someone is not thinking (attributed to Patton)

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Re: Section infantry weapons

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Little J wrote:Problem with M855 A1 (and its like) is that the barrel pressures have gone up so high that your safety margin to the proof load is almost halved...
If what is rumoured is true the new 6.8mm pressure ~50% higher than the M855 A1, will need new design and high tech which doubt will come cheap to keep the safety margins.

Secondly the 6.8 with the more powerful load and its bullet twice weight if not more of 556 will result in higher recoil, will it degrade the soldier ability to control the assault rifle in fully automatic fire mode?

Thirdly that high pressure creates heat, just guessing as no details have been revealed of powder load, heat may be double that of 556?, that will burn out barrels quickly, if you section an old barrel the rifling just past the neck looks like a dried up river bed, its cracked and it expands, which tears the bullet jacket ruining accuracy. To avoid that scenario expect 6.8mm barrels will need exotic steel and specialised tooling for machining, both expensive.

The 1940's British 280/30 round said to have ~2,500/2,600 fps from a 24" barrel with 140 gr bullet, whereas the new 6.8, 3,000fps from a 16" barrel with 135/140 grain bullet? Understand tech has improved, steels and powders etc, but pushing against any limits gets expensive, can be very expensive.

It will be of interest as more details forth coming of the 6.8, up to now US Army releasing very little info.

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Re: Section infantry weapons

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NickC wrote: more details forth coming of the 6.8, up to now US Army releasing very little
It was to be shooting all summer long; hope that happened (with Covid and all)
Ever-lasting truths: Multi-year budgets/ planning by necessity have to address the painful questions; more often than not the Either-Or prevails over Both-And.
If everyone is thinking the same, then someone is not thinking (attributed to Patton)

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Re: Section infantry weapons

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Aren't the US looking to a .338 calibre weapon to replace the 7.62 M240? As for the recoil from the 6.8mm, the weapons submitted have a long recoil similar to the Ultimax LMG that greatly reduce recoil and improve handling as a result. You could fire the Ultimax in a controlled manner on full auto one handed whilst standing up, they even had a female employee shot the weapon this way.

The US Army's requirement is for the weapons submitted to not exceed the recoil of the current M4 or M249 in service. All three have met this requirement through various means including the long recoil. The .338 GPMG has the same recoil as the M240 but is lighter. IT does however have far greater range. penetration and stopping power. As a result it may also replace a number of the superb M2 .50 Heavy Machine Guns as its performance nearly matches it but it weighs considerably less as does its ammunition. The M2 will not be totally replaced and a composite cartridge using a polymer casing has been developed to reduce the overall weight of the weapon system moving forward.

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Re: Section infantry weapons

Post by Timmymagic »

Little J wrote:556 isn't going away for a long, long time, the new 6.8 is all about "overmatch" at the expense of lower powered situations, i.e. room clearing.
If the US is serious about the need to confront a peer threat then they will have to change. Because the Chinese will be wearing decent body armour as well.

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Re: Section infantry weapons

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Lord Jim wrote:Aren't the US looking to a .338 calibre weapon to replace the 7.62 M240? As for the recoil from the 6.8mm, the weapons submitted have a long recoil similar to the Ultimax LMG that greatly reduce recoil and improve handling as a result. You could fire the Ultimax in a controlled manner on full auto one handed whilst standing up, they even had a female employee shot the weapon this way.

The US Army's requirement is for the weapons submitted to not exceed the recoil of the current M4 or M249 in service. All three have met this requirement through various means including the long recoil. The .338 GPMG has the same recoil as the M240 but is lighter. IT does however have far greater range. penetration and stopping power. As a result it may also replace a number of the superb M2 .50 Heavy Machine Guns as its performance nearly matches it but it weighs considerably less as does its ammunition. The M2 will not be totally replaced and a composite cartridge using a polymer casing has been developed to reduce the overall weight of the weapon system moving forward.

Thanks for your info especially note the limitations on recoil for the new 6.8 assault rifles and LMGs

Long recoil has a long history, one advantage is the low chamber pressure when camber opens after firing as the barrel and receiver locked together on recoil allowing time for pressure to drop to low level, disadvantage makes for more complex weapon with the moving barrel, only remember the WW I French LMG Chauchat using the system actually manufactured in large numbers in 100 plus years, the British Farquhar–Hill never made it into production.

The Singapore Ultimax LMG greatly reduces recoil but its not long recoil, Ultimax uses a 'constant recoil' system, explained in video, whereas long recoil system both bolt and barrel recoil and fires from a closed bolt.

Interesting times to see how the new 6.8 rifles cope with the higher recoil of the cartridge to keep to M4 levels and if able to keep costs to current levels with the added complications involved


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Re: Section infantry weapons

Post by Little J »

Textron's entry...
Note that on the rifle, the support hand is right on the ejection port...


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Re: Section infantry weapons

Post by Lord Jim »

NickC wrote:The Singapore Ultimax LMG greatly reduces recoil but its not long recoil, Ultimax uses a 'constant recoil' system, explained in video, whereas long recoil system both bolt and barrel recoil and fires from a closed bolt.
Thanks for the clarification and video. :thumbup:

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Re: Section infantry weapons

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It's all there: more effect at range (from @ 7 minutes, in the Textron one).

What is there not to like? Entering thru doors looked awkward, but the "SAW"man wouldn't be the one going first. Kinda cute the used links being spewed out thru a separate opening. Must wonder how 'everything plastic' will fare in minus 20-30 degrees, with the metal parts within it perhaps getting red hot
Ever-lasting truths: Multi-year budgets/ planning by necessity have to address the painful questions; more often than not the Either-Or prevails over Both-And.
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Re: Section infantry weapons

Post by NickC »

ArmChairCivvy wrote:It's all there: more effect at range (from @ 7 minutes, in the Textron one).

What is there not to like? Entering thru doors looked awkward, but the "SAW"man wouldn't be the one going first. Kinda cute the used links being spewed out thru a separate opening. Must wonder how 'everything plastic' will fare in minus 20-30 degrees, with the metal parts within it perhaps getting red hot
Heckler and Koch with Dynamit Nobel developed the 4.73 x 33 caseless telescoped round for the long recoil G11assault rifle with its complicated rotary breech for over 20 plus years, in 1993 Germany finally cancelled the contract for the G11 to replace the ~300,000 G3 7.62, as a result H&K were in financial difficulties due large debts used to fund development and BAE bought company and later sold it on.

One of the problems with caseless ammo compared to normal brass cartridge rounds, especially in machine guns with the high rates of fire the rifle chambers get very hot and the brass insulates the powder for short time in chamber whereas the caseless round more liable to "cook off" by self igniting the caseless propellant in the chamber, Dynamit further developed the special propellant with a 100 °C higher spontaneous ignition temperature.

In 2004 the H&K caseless telescoped round was licensed to US who further developed round using a plastic case, presume seeing result in above video.

Would note yesterday Google announced they would do away with all plastic in their packaging by 2025, so you can envisage some in Washington may not be happy if US Army buying many billions of plastic 6.8 rounds when there are alternatives.

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