stancrist said:

The drawback to making up one's own personal definitions is that it typically causes confusion.

This is why I mentioned it. Just in case it might happen.

stancrist said:

A "SAW" (Squad Automatic Weapon) can be a SCHV LMG; SCHV automatic rifle; full power, rifle caliber LMG; full power, rifle caliber MMG; or full power, rifle caliber automatic rifle.

I tend to prefer technical descriptions. The role doctrinal ones usually change over time and are not the same anywhere else.

stancrist said:

And not all machine guns fired from a bipod are LMGs. Below is a M240 MMG fired from bipod.

As far as I knwo the M240 is a GPMG and when its used from bipod its used in the LMG role and if its used from tripod its in the MMG role. MMG being defined by the use of a mount and being rifle caliber.
In German nomenclature there isn't a MMG. It its fired from mount its a HMG. If not its an LMG. But internationally HMG is used for non rifle caliber weapons fired from mount.

Could have been worse. He could have read some of the "three shots and then steel" stuff that was popular for a while back in the 19th century.

EmericD said:

I know at least one French captain that, having probably read too much reports from WWI, tried to do that with an AAN-F1, but the results were absolutely not satisfying. The ballistic of the 147 gr ball loading is closer to the Mle1906 .30-06 than to the 8 mm Mle1898D... 

I come back to 8.5x63 ... ;)

as regards 12.7 SAPHEI. what about replacing with 30x113 as has been suggested? Them guns are pretty light.And there are gas powered ones available. So, if starting from nearly scratch, I'd go
 

• 4.6x30
• 6.8x51
• 8.5x63
• 30x113

stancrist said:

That's interesting. I never heard of indirect fire with machine guns having been done in Afghanistan. Got link?

Besides what EmericD wrote I have read somewhere some time ago that the Brits experimented with it.

I know that the experience in Afghanistan has resparked the interest in the German Army for the use of MG from mount. The need was there. Early on there where few mounts available and only a few people trained on their use. This changed and the mounts where used quite extensively.

graylion said:

4.6x30
6.8x51
8.5x63
30x113

IMHO it makes little sense to have 8,5 and 6,8. Both are intended for long range use.
A true intermediate makes more sense. This could be used for rifles and infantry MGs.
8.5 for al other (GP) MGs and possibly sniper and marksman rifles.

I am not a fan of the 30x113. I don't really see the use. If you want HE trowing in a ligthweight package 40 mm HV does that. 30x113 guns will allways be to large and heavy for dismounted use. 40 mm AGLs are far better for this purpose. Maybe design a more modern version with a more streamlined grenade of the same weight to reduce flight time and improve accuracy.
If its about penetration 30x113 isn't great as well. It also has no KE projectile. A 20x139 mm AC is the better choice for that.

graylion said:

I come back to 8.5x63 ... ;) as regards 12.7 SAPHEI. what about replacing with 30x113 as has been suggested? Them guns are pretty light.And there are gas powered ones available. So, if starting from nearly scratch, I'd go   4.6x30 6.8x51 8.5x63 30x113

That won't be my winning lottery numbers.

The 4.6 x 30 mm is a handgun-power round that can't be used in a handgun. The company RADAR1957 is making harness for the MP7, to be able to keep it close to the body, but this harness also accept... the MP5. The MP7 is a good replacement for a SMG like the UZI (or the MP5), but it's not the PDW as initially envisioned, that was supposed to be <1.5 kg and <30 cm.

The 6.8 x 51 mm is a "super 7.62 mm NATO", with the same limits as the 7.62 mm NATO (mainly ammo weight and recoil). A good round for a vehicle-mounted MMG, but probably not what I would want for dismounted infantry.

The 8.6 x 63 mm is a superb antipersonnel round for long-range use, but will lack the payload of the 12.7 mm for anti-material job, and will probably offer very little improvement over the 6.8 mm.

The 30 x 113 mm is burning much more powder than any current infantry support weapon, and except for the increased MV and reduced explosive efficiency I wonder if it's very superior to the 40 x 53 mm for infantry use.

My bet would be:

1- a handgun round (choose one),

2- something like the 224 Valkyrie or the 6 mm ARC (but with a truly lightweight case) for most dismounted infantry use (PDW, IW, LMG/SAW/AR),

3- a 8 x 63 mm (or a 30-06 with 190 gr bullets) for MMG/tripod/vehicle/RWS use,

4- a 13 mm HMG (because KE rounds are cheap) and a 40 x 53 mm GMG (or the very good Russian 30 x 29 mm).

EmericD said:

- something like the 224 Valkyrie or the 6 mm ARC (but with a truly lightweight case) for most dismounted infantry use (PDW, IW, LMG/SAW/AR),

Do you see any advantage to higher-pressure variants of these cartridges?  Not necessarily 80,000psi, but more than the 52,000 psi used by the ARC to protect an AR15's bolt.  BTW, Hornady publishes "bolt gun" loads at 62,000psi for the 6mm ARC, but it is difficult to gage the performance increase vs the "gas gun" loads since since they used a 24" (610mm) barrel for "bolt" data and 18" (457mm) for the "gas gun".

EmericD said:

graylion said: I come back to 8.5x63 ... ;) as regards 12.7 SAPHEI. what about replacing with 30x113 as has been suggested? Them guns are pretty light.And there are gas powered ones available. So, if starting from nearly scratch, I'd go   4.6x30 6.8x51 8.5x63 30x113 That won't be my winning lottery numbers. The 4.6 x 30 mm is a handgun-power round that can't be used in a handgun. The company RADAR1957 is making harness for the MP7, to be able to keep it close to the body, but this harness also accept... the MP5. The MP7 is a good replacement for a SMG like the UZI (or the MP5), but it's not the PDW as initially envisioned, that was supposed to be <1.5 kg and <30 cm. The 6.8 x 51 mm is a "super 7.62 mm NATO", with the same limits as the 7.62 mm NATO (mainly ammo weight and recoil). A good round for a vehicle-mounted MMG, but probably not what I would want for dismounted infantry. The 8.6 x 63 mm is a superb antipersonnel round for long-range use, but will lack the payload of the 12.7 mm for anti-material job, and will probably offer very little improvement over the 6.8 mm. The 30 x 113 mm is burning much more powder than any current infantry support weapon, and except for the increased MV and reduced explosive efficiency I wonder if it's very superior to the 40 x 53 mm for infantry use. My bet would be: 1- a handgun round (choose one), 2- something like the 224 Valkyrie or the 6 mm ARC (but with a truly lightweight case) for most dismounted infantry use (PDW, IW, LMG/SAW/AR), 3- a 8 x 63 mm (or a 30-06 with 190 gr bullets) for MMG/tripod/vehicle/RWS use, 4- a 13 mm HMG (because KE rounds are cheap) and a 40 x 53 mm GMG (or the very good Russian 30 x 29 mm).

Hmm,

• 5.7x28
• 6.5x47 (but the thing is that 6.8x51 is liable to become the new standard, no?)
• 8.6x63 (or 8x64 maybe? ;) )
• 14.5x113
• 40x53

graylion said:

14.5x113

What do you want this legacy round for?
Its overpowered for anti personel use, large and heavy. While its outdated/not powerfull anymore for anti vehicle use.
The 14,5 is very close to a 20 mm AC round. The gun is also of similar size and weight. But it lacks the extra power of the KE round and the payload capacity.The

The 5.7x28 is virtually identical in performance to the 4,6x30. If one doesn't cut it the other won't as well.

To select the right cartidges for your mix you need to define what you want to do with them. Once you do that you get performance parameters that will narrow the selection down. This way the cartidges selected to the mix make sense and complement each other.

It 6,8x51 will become a new standard is currently completly uncertain. As EmericD said its basically a 7,62x51.

schnuersi said:

I tend to prefer technical descriptions.

Same here.  However, I don't know of anyone else who defines SAW = SCHV LMG.

I know of only two instances of an LMG being called a SAW, and one is not SCHV.

schnuersi said:

As far as I knwo the M240 is a GPMG and when its used from bipod its used in the LMG role and if its used from tripod its in the MMG role. MMG being defined by the use of a mount and being rifle caliber.

The US Army considers the M240 to be a MMG, regardless of what type mount is used.

PEO Soldier | Portfolio - PM SL - M240B/L/H 7.62mm Medium Machine Gun (army.mil)