Why the USMC should not buy the "IAR"

[F-15 Eagle]

i dont see the big hype about the IAR it delivers the simular amount of volume of supression fire. and holds the same amount of ammunition as other AR. The British, Russians and Chinese all basically keep their existing AR and install heavey barrels to compensate. It took the USMC this many years to convert an M-16 platform AR to a SAW. Its nothing special in my opinion just a rifle with heavier barrel. Firing from open bolt instead of a closed one.

They have been there and done that. The British tried to use the L86 LSW as the squad machine gun but they learned fast that volume of fire is important in suppressing the enemy. Later it was converted into a sniper rifle and it proved to be effective at the sniper role but the 30 round mags held it back in the AR role so the British Army went with the M249 SAW. I expect the same thing to happen to the USMC IAR funny how history likes to repeat itself.

The only successful mag fed support weapon is the Ultimax from Singapore since it had a reliable 100 round drum that did not jam in field conditions. If the USMC really want a good light support weapon that would have been the way to go. But they did not for reasons that are not clear but my guess is because the Ultimax is not an America design and thats the only reason. I would have been ok with the Ultimax but now the winning IAR will ether be from H&K, a SCAR version or from Colt. All of them are just assault rifles with heavier barrels the USMC did not learn anything from the past IMO and now they will learn the same way the British did in the 1980s...the hard way.

 

[Abraham Gubler]

He presumably means the L2A1 Automatic Rifle, the Australian/Canadian heavy barrel full auto FAL variant, also used by Israel, Belgium and Argentina.
Was there ever a L2A2 improved version?

Sorry about the typo about barrel change and yes I meant the L2A1. Which was the heavy barrel, full auto version of the SLR (aka L1A1, FAL). It was also known as the AR (Automatic Rifle) alongside the SLR (Self Loading Rifle). The A2 typo came from mental association with the F2A2 which was an Australian designed AR with a range of improvements over the L2A1. its one of the stories within the Australian Army of the 70s and 80s about how good the F2A2 was and how outrageous it was that it was never ordered for production.

You can see a few attached pictures of the F2A2 which was similar to the L2A1 but fitted with a heat shield and several other improvements. Like a non-folding charging handle so it is clear of the barrel and an improved stock. The bipod was smaller necessitating issue of 20 round magazines.

 

[Abraham Gubler]

They have been there and done that. The British tried to use the L86 LSW as the squad machine gun but they learned fast that volume of fire is important in suppressing the enemy. Later it was converted into a sniper rifle and it proved to be effective at the sniper role but the 30 round mags held it back in the AR role so the British Army went with the M249 SAW. I expect the same thing to happen to the USMC IAR funny how history likes to repeat itself.

You are significantly misleading the history of the SA80 LSW to support your own preconceived beliefs. The SA80 was a failed LSW not because it fired from a 30 round magazine and lacked a changeable barrel. it was a failure because the rifle was so lacking in robustness that you couldn't shoot a 30 round magazine in a few long bursts without it jamming. The failures of the SA80 are well reported and stem from its design being a rough 'bullpupping' of the AR18 rather than an intentionally designed weapon. It also fires from a closed bolt meaning that after a burst of fire the bolt closes a round in the breech where the entire action (and round) are subjected to very high temperatures without a chance to cool down.

The USMC IAR is a very different weapon to the SA80 and the tendered weapons are far more robust with an open bolt (for cooling) option. There are many other ARs that are highly successful like the HK weapons, the Steyr AUG LSW, the RPK, the FAL AR and the WW2 weapons.

The only successful mag fed support weapon is the Ultimax from Singapore since it had a reliable 100 round drum that did not jam in field conditions.

Again that's not true. There are several ARs out there that are highly effective and well respected.

You persist in making this knowledge poor statements to support your on paper based belief.

 

[F-15 Eagle]

[FONT=verdana,arial,helvetica]Abraham Gubler[/FONT] I'm done talking to you and I'm not going to respond to your posts anymore because you keep insisting that I'm somehow making things up just to voice my opinion which I'm really making my opinion off of the facts that I have learned about mag fed weapons for the support role. As I have said 30 round mags are not enough and history has proven that a large volume of fire is need for the support gunner and reliability was not the only issue with the L86 LSW. It was both the small 30 round mags and the barrel, both the British and Danish solders have stated that. Of course you will not agree but don't respond because I wont reply and I am done wasting my time with you.

 

[regstrup]

And the magazine LSW is not a proven failure, its won quite a few wars and will probably do so in the future.

True, that the magazine LSW has fought some wars, but they have never won any. Good soldiers with good leadership and good logistics win wars.

If you have a light enough GPMG, you don´t need the M249 for sustained suppression.

This is so true, dobrodan.

The challenge that the danish soldiers face in the green zone of the Helman river is, that they can’t always relie or expect covering fire from the other squads in the platoon because of the dense plantation. The plantation dosen’t give very good visibility and most of the fighting is done at ranges from 5 to 50 meters. So it is important that the squad can deliver its own suppressingfire.

I know a lot of danish soldiers, who either has been in Helman or are there right now. They all say, that the Diemaco LSW with its 30 round mags can’t give the suppressingfire, they need. Actually the Taliban is better equipped with the PKM.

If you gave any danish squadleader the option between the Diemaco LSW or the PKM as a replacement for MG3, they would go for the PKM, because it is beltfeed, has a 100 round magasine, a detachable barrel and is much lighter than the MG3.

Only the future can show, if the IAR can do the job over a beltfeed LSW, but I seriously doubt it. Neither dobrodan (who sounds like a reasonable guy) or Abraham Gubler has come any arguments, that has conviced my, that the IAR will become a succes.

But I wouldn’t mind to be proven wrong. Luckely the US fight a lot of wars and the grunts are best judges, so we will have to see, what their verdict of the IAR is.

 

[Abraham Gubler]

I know a lot of danish soldiers, who either has been in Helman or are there right now. They all say, that the Diemaco LSW with its 30 round mags can’t give the suppressingfire, they need. Actually the Taliban is better equipped with the PKM.

If you gave any danish squadleader the option between the Diemaco LSW or the PKM as a replacement for MG3, they would go for the PKM, because it is beltfeed, has a 100 round magasine, a detachable barrel and is much lighter than the MG3.

No one is talking about replacing 7.62mm GPMG (like the PK) with an 5.56mm AR (like the IAR) but what we are seeing is a revelation that the replacement of 7.62mm GPMGs with 5.56mm LMGs (or 5.56mm ARs in some adventurous armies) in the section/squad was a mistake. To compare the Dimaco LSW with the PK is crazy because of the huge increase in firepower of a 7.62mm over 5.56mm weapon.

More and more 7.62mm GPMGs are being returned to the section teaming and the 5.56mm AR is seen as providing suppressive fires to the sub-section fire team. This is why FNH are now building their Minimi in 7.62mm (the Mk 48) and the Marines are acquiring the IAR.

Also 7.62mm designated marksman rifles are being issued to sections splitting the old single bullet per section adage right down the middle. Which is fair enough to get maximum performance from the unit. Horses for courses as the old saying goes.

 

[ReAl PrOeLiTeZ]

They have been there and done that. The British tried to use the L86 LSW as the squad machine gun but they learned fast that volume of fire is important in suppressing the enemy. Later it was converted into a sniper rifle and it proved to be effective at the sniper role but the 30 round mags held it back in the AR role so the British Army went with the M249 SAW. I expect the same thing to happen to the USMC IAR funny how history likes to repeat itself.

The only successful mag fed support weapon is the Ultimax from Singapore since it had a reliable 100 round drum that did not jam in field conditions. If the USMC really want a good light support weapon that would have been the way to go. But they did not for reasons that are not clear but my guess is because the Ultimax is not an America design and thats the only reason. I would have been ok with the Ultimax but now the winning IAR will ether be from H&K, a SCAR version or from Colt. All of them are just assault rifles with heavier barrels the USMC did not learn anything from the past IMO and now they will learn the same way the British did in the 1980s...the hard way.

not true your whole post, the RPK and T-95 LSW deliver large amounts of volume simular or equivalent to the M-249. yet it still an adaption from rifles in service converted to fill the role of SAW/LSW. rifles were also adapted and converted to DMR.

 

[regstrup]

More and more 7.62mm GPMGs are being returned to the section teaming and the 5.56mm AR is seen as providing suppressive fires to the sub-section fire team. This is why FNH are now building their Minimi in 7.62mm (the Mk 48) and the Marines are acquiring the IAR.

A danish squad only consists of six (6) men, so they don't have the manpower to drag along a 7.62 GPMG og MG3 with ammunition. So that is why a beltfeed LSW is prefered for extra firepower.

There are talks about buying the MG4 or the FN Minimi in 5.56mm to replace a Diemaco LSW in the squad.

A suggestion is also to replace it with a Minimi in 7.62mm. If that dosen't work out, it can be transfered to the supportplatoon or be vehiclemounted and the squads will then be issued a MG4 or Minimi in 5.56mm.

But as you se, there is a huge difference in the number of men in the danish squad compared to the Marines.

 

[dobrodan]

A danish squad only consists of six (6) men, so they don't have the manpower to drag along a 7.62 GPMG og MG3 with ammunition. So that is why a beltfeed LSW is prefered for extra firepower.

There are talks about buying the MG4 or the FN Minimi in 5.56mm to replace a Diemaco LSW in the squad.

A suggestion is also to replace it with a Minimi in 7.62mm. If that dosen't work out, it can be transfered to the supportplatoon or be vehiclemounted and the squads will then be issued a MG4 or Minimi in 5.56mm.

But as you se, there is a huge difference in the number of men in the danish squad compared to the Marines.

Well, here´s a nice link that describes (with photo and video) how it feels to shoot both the Mk46 (5.56) and the Mk48 (7.62) And if you follow the links on the site, there´s a few more interesting guns to be found as well...

http://www.militarymorons.com/misc/vltor3.html

Still, what this guy says about the Mk48 is that it kicks quite hard, and while lighter than the M240, it´s not very user friendly...

The Mk46 seems like a decent gun, but to be of any serious use, it would need a heavier barrel. And even a spare barrel...

One of the reasons I like the concept of the IAR is that I loathe spare-barrels...
This because it´s really unpleasant and unpractical to carry it. But still, it is there for a reason, and when only having one MG in the squad, like in Norway, you need to keep it running all the time, or take the consequenses... And that is not because you may overheat the barrel... While it´s possible to do it, in an emergency, the barrel (of the MG3) will handle more than 1000rds in ONE burst without physically destroying (metallurgically, that´s another story) The real problem is getting a cartridge jam in the chamber, or breaking a bolt... If you don´t have spares then, you may be in deep trouble.

But, with several MGs in a squad, or even in a fire-team, the need for spares will decrease, because you will still be able to give suppressive fire from one gun, while repairing the other, and ultimately, with a QCB-equipped gun, if you have a total failure (most likely bolt), you can still use the barrel for the other gun...

But, ultimately, I would rather have two 7.62 GPMGs in one fireteam, than six Mk46 in three fireteams, because while fairly light, the Mk46 is a bit more unwieldy than the IARs, especially with the 200rd box. And with the 100rd pouch, it is light, but takes some time and effort to reload. With only one fire-team equipped with GPMGs, the rest of the squad should be very mobile and able to quickly engage the enemy with a lot of firepower while the GPMG-gunners and assistants prepare their positions and guns. While the 7.62 GPMGs are a bit heavier than a MK46, the fact that the rest of the squad is able to put out an extremely high volume of fire immediately on contact, should give the GPMG-gunners time to move to a good position before getting engaged in the fire-fight. And then the squad will have a lot more punch against a prepared enemy.

And about the MG4: I feel it is a GPMG made in 5.56... It is very heavy, and the belt-box is mounted offset to the left, getting in the way of carrying the gun... It will probably one day arrive in 7.62-version, but even then I feel the PKM has a much better layout, while being lighter than the 5.56 MG4...

 

[F-15 Eagle]

I know a lot of danish soldiers, who either has been in Helman or are there right now. They all say, that the Diemaco LSW with its 30 round mags can’t give the suppressingfire, they need. Actually the Taliban is better equipped with the PKM.

If you gave any danish squadleader the option between the Diemaco LSW or the PKM as a replacement for MG3, they would go for the PKM, because it is beltfeed, has a 100 round magasine, a detachable barrel and is much lighter than the MG3.

Only the future can show, if the IAR can do the job over a beltfeed LSW, but I seriously doubt it. Neither dobrodan (who sounds like a reasonable guy) or Abraham Gubler has come any arguments, that has conviced my, that the IAR will become a succes.

But I wouldn’t mind to be proven wrong. Luckely the US fight a lot of wars and the grunts are best judges, so we will have to see, what their verdict of the IAR is.

I don't mind if the IAR would complement the SAW but not replace it like another tool in the toolbox so to speak. They should have both but I don't think the IAR can replace the SAW, it would be better if they serve with each other thats the only way the IAR could be a success.

not true your whole post, the RPK and T-95 LSW deliver large amounts of volume simular or equivalent to the M-249. yet it still an adaption from rifles in service converted to fill the role of SAW/LSW. rifles were also adapted and converted to DMR.

Ok you got me there but I thought the RPK is belt-fed or am I thinking of something else?

 

[dobrodan]

RPK is magfed (basically a long AK with bipod)
RPD is beltfed (MG in 7.62x39)
PKM is beltfed (MG in 7.62x54R)

Now, I found a interesting clip of the KAC LMG, a beltfed weighing 4.5kgs...

http://www.silencertalk.com/videos/PDW-LMG-HD.wmv

http://www.knightarmco.com/lmg.html

Seems to be a quite interesting gun, if it is reliable, and with a bit longer, changeable barrel, it could be very useful... It is small and light enough to be handled more or less like an assault-rifle...

This should be able to handle most roles the IAR could do as well, except a "DMR"-ish role...

 

[Abraham Gubler]

Seems to be a quite interesting gun, if it is reliable, and with a bit longer, changeable barrel, it could be very useful... It is small and light enough to be handled more or less like an assault-rifle...

I doubt they could keep it so light with a longer barrel, changeable barrel. Not only would this add weight for the extra barrel length and rapid change mechanisms but a 12.5" barrel reduces recoil potential because the 5.56x45 bullet doesn't have enough barrel length to reach full velocity (-11%). This would mean heavier recoil springs, etc all pushing up weight from the 4.5kg mark getting closer to the 6kg of the FNH Mk 46.

 

[dobrodan]

I doubt they could keep it so light with a longer barrel, changeable barrel. Not only would this add weight for the extra barrel length and rapid change mechanisms but a 12.5" barrel reduces recoil potential because the 5.56x45 bullet doesn't have enough barrel length to reach full velocity (-11%). This would mean heavier recoil springs, etc all pushing up weight from the 4.5kg mark getting closer to the 6kg of the FNH Mk 46.

Well, it already seems to have a much heavier barrel-profile than the Mk46, so I doubt a slightly longer, 16", preferrably finned barrel would add very much weight... Neither would a similar Ti bipod as the Mk46 uses, or even some grip-pod stuff (I don´t really know how good these are, but they may be useable)

On the other hand, I am not too sure any extra barrel-length would mean more recoil... I would believe the opposite would be more likely, as the expanding gases create a lot of recoil-force when they are exiting the barrel. Adding a silencer to a large-calibre gun will take away a lot of the recoil... Also, I have a friend that owns an 7.92 K-98 "Gebirgsjägerkarabine", and it is very much shorter than a normal 7.92mm K-98, and kicks much harder.

I would expect a 16" model with a bipod to weigh just above 5kgs... And the extra weight should even make it more controllable...

Here´s another video:

http://www.youtube.com/watch?v=DV6WHA2efm4&feature=related


IMO, it´s quite impressive!

 

[Abraham Gubler]

Also, I have a friend that owns an 7.92 K-98 "Gebirgsjägerkarabine", and it is very much shorter than a normal 7.92mm K-98, and kicks much harder.

That is a very different arrangement. The difference in barrel length does not effect the velocity of the 7.92mm because it has already had the effect of the full propellant burn. The longer barrel just provides better stability through more spinning. The shorter barrel reduces the weight of the weapon which is why you have more recoil for the same bullet performance.

In the case of the 5.56x45 there is no noticeable difference between the recoil caused by the propellant and different barrel lengths but the shorter sub 18-20" barrels reduce bullet velocity because not all the propellant is burnt by the time the bullet leaves the barrel. In the case of a 12.5" barrel this reduces muzzle velocity by 25% (I didn't use M855 ammunition as by base in the earlier calculation). The effect this would have on the recoil impulse is a reduction of about 16% assuming the weapon is of similar weight.

 

[dobrodan]

A sign of the propellant not being perfectly burnt is a large fireball from the muzzle... The short-barreled K98 has that, but the regular K98 does not have anything close...

Well, anyway, it´s still 5.56, so it should not kick extremely hard anyway...

But, why would it need heavier recoil-springs? The bolt locks until the pressure reaches a safe level, right? This you should be able to adjust with the size of the gas-port in the barrel (or add a gas-regulator)

 

[Abraham Gubler]

A sign of the propellant not being perfectly burnt is a large fireball from the muzzle... The short-barreled K98 has that, but the regular K98 does not have anything close...

Well no doubt you know more about this weapon than I do. The only Mauser I’ve ever fired was an ex Israeli 7.62x51mm conversion. But the effect of the propellant not burning on recoil is marginal it would actually lower recoil as more of the propellants mass (over 3g for 7.92mm) would be leaving the weapon at lower than burnt gas velocities (1,200 mps). The effect on the muzzle velocity would depend on the actual weapon. What is likely however to cause more recoil is the lowered weight of the overall weapon. The bullet and gas leaving the barrel just create the recoil impulse. Energy of recoil depends also on the weight of the weapon.

But, why would it need heavier recoil-springs? The bolt locks until the pressure reaches a safe level, right? This you should be able to adjust with the size of the gas-port in the barrel (or add a gas-regulator)

By that gross simplification I mean that if KAC have cut weight by tailoring their Stoner LMG to the performance of the bullet in the 12.5” barrel (which they can do) they would have to add that weight back in for a longer barrel and higher velocity bullet. By this I mean less gas being tapped, less vibration, less recoil energy on the bolt locks, etc. Not quite in the same league as the difference between 7.72x51 and 5.56x45 but still something.

Also there would be additional weight in the barrel. As much as 25% to go from 12.5” to 16” length. Using the Minimi as a base barrel this would be as much as 0.5 kg for an extra 3.5”.

 

[dobrodan]

Remember that the peak-pressure will be when the round is just past the chamber, which means at that point the forces on the locking lugs will be highest.
As the acceleration of the bullet decreases because of lower pressures, the forces on the lugs will decrease.
This is the same in a long and a short barrel, but in a long barrel, the gas-port won´t have to be as large, because the pressure will remain relatively high for a longer duration of time, and this should actually decrease the stresses on the gun, as the gas-piston receives a slower build-up of pressure, which again unlocks the bolt slightly slower, with the result that the pressure in the barrel may be lower at the time of unlocking, thereby slowing the ROF slightly.

As an addition, the KAC LMG has the same kind of recoil-absorption system as the Ultimax. The bolt is always floating on the recoil-spring, and never hits the back of the receiver... Thereby giving a very smooth felt recoil.

 

[ReAl PrOeLiTeZ]

I don't mind if the IAR would complement the SAW but not replace it like another tool in the toolbox so to speak. They should have both but I don't think the IAR can replace the SAW, it would be better if they serve with each other thats the only way the IAR could be a success.



Ok you got me there but I thought the RPK is belt-fed or am I thinking of something else?

you probably thinking the heavey PKM/RPD, though they are meant for GPMG simular to the M60

 

[F-15 Eagle]

you probably thinking the heavey PKM/RPD, though they are meant for GPMG simular to the M60

Right, but now the M60 has been replaced by the M240 its a bit heavier but it has a much higher rate of fire, 750, 850 and 950 rounds per minute it has a selective fire option and it resembles the German MG 42 in a way with the high rate of fire.

 

[dobrodan]

Right, but now the M60 has been replaced by the M240 its a bit heavier but it has a much higher rate of fire, 750, 850 and 950 rounds per minute it has a selective fire option and it resembles the German MG 42 in a way with the high rate of fire.

Not quite...

Because the M60 was unreliable, and not very user-friendly, it got replaced by the M240...

I can not ever remember to hear that the M240 have a selective fire option, except that you can change the gas-regulator settings, and adjust the ROF that way... On the max setting its supposed to fire 1000 rpm. Still a bit behind the 1200rpm for the MG42/MG3...

Oh, and the RPD is not a GPMG, just a LMG...