Time to upgrade NATO smallarms calibres?

HAVE YOUR SAY

NATO must switch to 6.8mm
the 5.56mm is useless.
I was gutted when I had to change my 7.62mm SLR for the SA80 5.56mm.
I knew if I slotted a7.62mm round into anyone, they wouldn't get up, with the 5.56mm, you had double tap twice, once to put him down, and once to keep him down.
The 5.56mm was alright in FIBUA and close contact in jungle and heavy forest, but when you have a drug crazed gunman, either in Somailia or Sierra Leone and in sone cases in Afganistan charging at you, with no fear, a 7.62mm round would put him down, leaving him a very nasty exit hole.
With the SLR, it was also handy for cracking a few skulls, the SA80 would fall to bits.
In my view, the MOD should have kept the SLR, modified it as par the FN para model, used lighter materials on the body, made a mag to hold 25 or 30 rounds.
The MOD had to have a 5.56mm weapon,they panicked, picked the SA80, which was designed in the 1950's, it took many years and a lot of expensive modifications, to make it,what it is now, a very accurate and reliable weapon. But the 5.56mm round is not up to the job.
I have fired a Stoner assault rifle in 6.8mm, it uses a large amount of m16 parts, it is truely a awesome piece.

john

Looks like the US is well ahead on this matter. Believe this calibre is been sold as a hunting rifle for the time being.
Chris - Keighley

MOD has just signed,a contract for a number of (440) LM7 semi automatic rifles,7.62mm,to enable our troops to engage the enemy upto 800m, it weighs 5kg, comes with a 20 round magazine, its length is 945mm,comes with a unidentified scope, reports says its a awesome piece of kit
john - iom

Renamed the L129A1 for UK purposes, should be easily converted to 6.8 if needed. Though whether the Government would eventually ditch the SA80 for this type AR, or cling onto the former like a dog to a gnarly old bone is another question.
Chris - Keighley

My view is that 5.56 (.223 REM) is fine for short range work but something bigger is needed for longer range. Energy =1/2 (mass x velocity squared). 6.8mm (essentially a repackaged 270 WIN with a shorter case) is a powerful cartridge and fully automatic fire begins to be harder to control. In truth you probably need both and this can be achieved with Modified Upper Receiver Group (MURG)rifles where you can switch between the two. There are three plus one things to consider; the gun, the cartridge, the bullet. Finally the interaction between them. 7.62 x 51 (.308 WIN)is a superb cartridge but awful in an FAL or M14 (both superb rifles in semi automatic mode)on fully automatic. Whatever happened to .280 Enfield (developed for the EM2) a superb cartridge in all respects?
John Walkley - Budapest Hungary

Believe the .280 was rejected by the US as not powerful enough. Was this the round originally intended for the SA80, to stop it falling into enemy hands. Given the US probably uses the most and is heavily dependent on all it's munitions manufacturers. Then the US will probably always lead the way with Nato calibres.

Chris - Keighley

No reason why a 6.8mm rifle could not be a bullpup such as a Steyr Aug, FN2000 or even a new, properly built,debugged SA80.
I also think we need something to fill the gap between the 7.62x51 & .338 Lapua. The 6.5x55 is loaded to only 45000 psi for the safety of old rifles. If it was necked up to 7.62 & pressure raised to the 52000 of 7.62x51, then it could be the one. A 7.62x55 would be the most powerful cartridge the average soldier could cope with, though it would have to be kept below 4500 joules to be safe on most ranges.
Say;
9mm Para replaced with .40 S&W
5.56mm replaced with 6.8mm SPC
7.62X51 replaced with 7.62x55
Yes?
John Hartley - Woking/England/UK

Does anyone really want to revisit the nightmare of SA80? At least given the only reason it came into being is that it was supposed to be the cheapest option available. Then had to be completely reworked to make it acceptable. The SAS wouldn't touch it and it caused a great deal of upset to those that did. Can only be seriously used right handed, dodgey on the hearing and all the other little ailments attributed to it.

Chris - Keighley

Adopting 6.8mm as a 3rd NATO caliber or replacement for 5.56mm would be rather knee-jerk. The problem that 5.56 and also the current 7.62mm have is that their Bullets are not the ideal ballistic shapes. The old US 5.56mm was dreadful and only marginally improved by the FN SS101 NATO standard adopted in the 1980's. Examples of ballistic perfection were the .303Mk8Z and the German 7.79 Heavy Round both used to achieve 4000+yds in SF roles. The .280 designed for the EM2 was also had a high ballistic coefficient (BC. The best offering so far is the 6.5mm "Grendel" round. This 6.5 mm caliber intermediate cartridge was developed in 2002 by Bill Alexander of Alexander Arms (a Brit) and Arne Brennan of Competition Shooting Sports. The Grendel design philosophy has been summarized as "start slow and end fast". High muzzle velocities accelerate barrel wear and increases the percentage of recoil due to wasted escaping gases, but only yields good impact energy if the bullet is efficient at carrying its velocity downrange. Constrained by the length of the 5.56 mm NATO round, but wanting to launch a much heavier bullet, the Grendel designers decided to use a short, fat case for higher powder volume while saving space for long, streamlined, high "BC" bullets that give up little of their in-flight energy. It therefore actually outperforms the current 7.62 NATO round beyond 800m, but with less recoil and due the Cartridge base and overall length equating to the current 5.56, it limits conversion requirements for current 5.56mm rifles. I believe the current 30rd SA80 Magazine will fill with 25 of the fatter Grendel rds. The 6.8mm Remington SPC is better than 5.56mm, but not good enough that you could also replace 7.62mm. With Grendel you could standardise on 6.5mm along with .338 and .5 phasing out 7.62mm eventually, as 6.5mm SAW and GPMG came into service.
Harry - Salisbury/UK/Retired

The Americans have been debating 6.8mm SPC versus 6.5mm Grendel. Either is better than the 5.56mm, but most think the 6.5 is a better 1000yd special forces cartridge. However for "Big Army" the 6.8mm is a better 400m battle round for ordinary troopers & will work better through LMGs. More experimentation is needed. For example, has anyone tried a 120 grain FMJ target boattail bullet in 6.8mm. That could narrow the gap longrange with the 6.5mm. An alternative would take the 123 grain 6.5mm bullet & fit it to a slightly necked down SPC case, for a best of both hybrid.
John Hartley - Woking/England/UK

I think that wrote the article below got it right: http://www.chuckhawks.com/definitive_service_caliber.htm
(2 parts)

The 6.8mm Remington Special Purpose Cartridge still does not have enough poop. Neck down a 7.62x51 NATO use a 150g(6.8mm) .270 Spitzer boat tail bullet.

Just like the .50 cal snipper rifles need more poop to full fill the role of anti -material http://www.6mmbr.com/compcartridges.html.

http://ammoguide.com/cgi-bin/ai.cgi?sn=BNWjwDRiqM&catid=445
Josh Thurston - Canada

Having read the science behind ballistics and personal testimonies of 5.56 NATO and M16 derivatives I believe the solution for future conflicts would be a UK assault rifle & belt fed GPMG based on an intermediate cartridge of 6.5mm or 7mm. This cartridge will have the same or better performance at 7.62 NATO, but have less recoil and controllable on full automatic fire. This includes importantly stopping power and suppression upto 800m, and consistent terminal effectiveness and the characteristic of not being diverted easily on the way to the target by vegetation or manmade barriers. I believe a second option to Commanders in the field should also be made available, as has been proved by recent events in Afghanistan. The option of a second heavier cartridge that would be used in a LMT Sharpshooter-like rifle and a heavier belt fed machinegun both of the same calibre but a longer cartridge the bullet would also have a longer heavier design probably akin to the British .276 Enfield or .256 British MK1 ( 100 year old designs), this having a flatter ballistic profile and high mass to deliver at range with less drag. The LMT sharpshooter rifle is a great addition to the 5.56mm NATO and proved not just to be a stop gap but a real asset at long ranges in Afghanistan (mainly due to the optics & floating barrel as well as it's 7.62 cartridge). A heavier machinegun using the same calibre could also not only be carried (individually) or crew-served(in-direct fire) but fitted to vehicles and helicopters. Give the soldiers the option to carry two calibres if the environment dictates that they need it. Or Just carry the intermediate calibre system with one cartridge type! They have to carry the ammunition into battle after all so give 'em the choice!
Perhaps the UK assault rifle could be a Kel-tec RFB-like design, forward ejecting bullpup ambidextrous, FAL metric magazines, NATO rail system, open for discussion I Think?
Compare below cartridges, The SDR figure shows the superior effectiveness over 5.56 NATO.

0.276 (7x60mm) Enfield SDR = 0.29 bullet=10.8g velocity=2800 fps

0.256 (6.5x50SR mm) British MK1 SDR = 0.28 bullet=9.1g velocity=2500 fps

0.280 (7x43 mm) British SDR = 0.24 bullet=9.1g
velocity= 2530 fps

5.56 NATO SDR =0.17 Bullet=4g Vel = 3110 fps

7.62 NATO SDR =0.21 Bullet=9.3g Vel = 2800 fps
Simon J - Portsmouth

Is the British army change the sa80 a2 assault rifle to the l129a1 sharpshooter rifle
Staff Sargent hearne 1 para - dartford England britsh army

John/Chris,

The SA80 wasn't designed in the 1950's, it's a badly re-wrapped AR-18.
The 1950's rifle was the EM-2, the bullpup rifle that the .280 British cartridge was created for to allow for controllable automatic fire with a man-stopping cartridge.
It was briefly adopted by the UK Armed Forces as Rifle No.9 Mk1 (1951), then withdrawn when the US insisted on the 7.62x51mm T65 cartridge as the NATO standard round. The .280 had better performance out to 1000ft due to the superior ballistics of the projectile.
The Bren & Vickers were to be replaced with the .280 Taden Gun as a GMPG.
The L1A1 was a rush adoption of a re-calibred FAL, which had also originally been developed for the .280, but was better suited to the T65 round.
All of the post-WW2 US rounds have been based on civvy hunting/sporting cartridges, including the 6.8mm SPC.
Andy F - Glossop, UK

You can stay with the 5.56mm, but you need the ability to throw away barrels. Because of the hot loads, so the SA-80, Aus Steyr, long barrels, hot loads and easy replacement. It is not possible for infantry to throw away guns like Delta or the SEAL's, back to the armory for barrel changes due to the hot loads. very hot loads through the M4. As hot as you can go without seizing the bolt or wearing it in the head. So you can load the 5.56mm to a mild NATO 6.8mm standard. But it is barrel length. In the end the US will go bullpup, it is the only way. Colt will do it, the M16 design is past its date and the M4 shows it. Performance shows that, compact, 5.56mm, barrel length.
Matt