New Army "Caliber Configuration Study"

[JASmith]

Against soft-skinned vehicles: Probably.

Against light armored vehicles: Doubtful.

Do you have numbers to back up these guesses?

[cory]

Hornady's 9th Ed. reloading manual has .338 LM at an ~MV of 2800fps at max pressure with a 250gr BTHP (B.C. 0.670) out of a 24.5" barrel.

Barret lists 50 BMG at a ~MV of 2750fps with a 29" barrel and 2500fps with a 20" barrel, both with a 661gr (what looks to be a BTHP) (B.C. 0.62). So for comparison to the .338 LM we could say 2625fps MV for the 50 BMG.
http://www.barrett.net/ammunition/50bmg

I'm not sure how using a .338 Norma Magnum would change the MV.

All that being said, I think it's fair to say the .338 won't be as effective as the .50, but will it be effective enough to meet mission requirements.

[stanc]

I think that the proposed .276 Penderson and the .280 British (the 7x43mm version) could have been GPC's. They were intended for individual weapon and LMG use. I don't know if they were to be used in the MMG role, however.

IIRC, a .30-cal M1917 HMG was converted to .276 Pedersen. (The US did not have MMGs in WWII, only air-cooled LMGs and water-cooled HMGs.) However, .276 Pedersen may not have been a good GPC, as it reportedly was inferior to .30-06 in armor penetration.

Ironically, the Japanese had the 6.5mm Arisaka and the Italians had the 6.5 Carcano, but both initially used round-tipped bullets which had poor terminal ballistics. They both decided to move up to to a larger caliber. I do not know if the Japanese reevaluated the 6.5 Arisaka after switching to the pointed bullets which would yaw after impact.

The Japanese adopted spitzer bullets for 6.5 Arisaka prior to the First World War, so they would've had plenty of time and opportunity to evaluate it in combat.

[stanc]

Do you have numbers to back up these guesses?

7.62mm is the standard chambering for US tank co-ax machine guns, and M80 Ball does a good job of ventilating auto and truck bodies. What a .308" 147gr bullet can do, a .338" 300gr projectile ought to do even better.

[JASmith]

7.62mm is the standard chambering for US tank co-ax machine guns, and M80 Ball does a good job of ventilating auto and truck bodies. What a .308" 147gr bullet can do, a .338" 300gr projectile ought to do even better.

The question refers to the .338 vs .50 cal and the metric is whether "good enough" holds.

You can see that Cory is getting us close to an answer. "Doubtful" still needs to be backed up with numbers.

[Michael]

(The US did not have MMGs in WWII, only air-cooled LMGs and water-cooled HMGs.)

Incorrect. M2 Browning was in service and considerd a heavy machine gun. M1919 was considerd a medium machine gun. BAR was considered a light machine gun.

[stanc]

.338 Norma Magnum -- 300gr @ 2650 fps in GD LWMMG
.50 Browning M33 Ball - 660gr @ 2910 fps in M2HB (velocity @ 78 ft from muzzle)

[stanc]

M1919 was considerd a medium machine gun. BAR was considered a light machine gun.

Not by the US Army, they weren't. The M1919 was classified as a light machine gun, and the BAR as an automatic rifle. (The initials "BAR" are an abbreviation of Browning Automatic Rifle.)

9:30-12:00
[video=youtube;8KqemCtq3B8]http://www.youtube.com/watch?v=8KqemCtq3B8[/video]
http://www.youtube.com/watch?v=8KqemCtq3B8

5:30-6:00
[video=youtube;Oyj-ZHXFKQI]http://www.youtube.com/watch?v=Oyj-ZHXFKQI[/video]
http://www.youtube.com/watch?v=Oyj-ZHXFKQI

[stanc]

"Doubtful" still needs to be backed up with numbers.

No, it doesn't. It's a statement of opinion, not verifiable fact.

[joker31]

You said that in one fight, "My team alone expended 3200 Rounds in 8.5 hours..."

Doesn't that argue for the smallest, lightest cartridge feasible, so as to maximize the number of rounds carried?

Since the infantry squad currently has two M249 LMG's, I presume you mean add one in a larger caliber? Doesn't that contradict your statement above?

Not exactly, we could have never carried that much ammo on our backs along with all the other crap we had to carry, I had 100Lb+ of gear alone for my role in the mission. We were using vehicles up to a point where we had to leave them, then set up a cache site and set an overwatch over it then my team went into the village, the helo's were dropping it from about 40ft in body bags (Speedballs) One semi bad-guy I knew that was fighting against us later told my team mate that they thought we were dropping in robots to fight because we never stopped advancing, we advanced like robots right towards them and some guys were shot and didnt fall down.... was kinda funny. It really hurts morale when you think your fighting an indestructible enemy. My battle load was 350 rounds of 5.56 in Pmags 11 30rounders and one 20 rounder with tracers for 10.5in M4, 120 rounds of 7.62 for my M14 EBR, went in country with a Leupold, turned in with a NF on it. then was issued a KAC SR-25 and Pmags with a NF but never got to use it in Combat.

Pistol was a Sig M11.

[Michael]

Not by the US Army, they weren't. The M1919 was classified as a light machine gun, and the BAR as an automatic rifle. (The initials "BAR" are an abbreviation of Browning Automatic Rifle.)

In the context of the ongoing discussion, the BAR was employed as the SAW/IAR of its time, while the M1919 was employed the M240G of its time; hence the terms used are relevant to the discussion.

If you look at the criteria I posted earlier of Light v Medium v Heavy, they also fit the parameters. I will add some additional criteria that I think should be fairly widely accepted;

Light – Employed by single person (BAR, SAW, IAR)
Medium – Employed by a team (M1919, M60, M240G)
Heavy – Employed by a team, but due to system/ammo weight/bulk, normally fixed or vehicle mounted (M2, M1917, Mk19)

[JASmith]

...additional criteria that I think should be fairly widely accepted;

Light – Employed by single person (BAR, SAW, IAR)
Medium – Employed by a team (M1919, M60, M249G)
Heavy – Employed by a team, but due to system/ammo weight/bulk, normally fixed or vehicle mounted (M2, M1917, Mk19)

Many thanks!

Those are very useful definitions, and now I know where the Dillon Gatling guns fit. I have been told by Dillon that the "water stream" of red from the tracers means that sights are rarely used, but the gun is almost always a vehicle or fixed mount, Arnold S. notwithstanding.

[stanc]

In the context of the ongoing discussion, the BAR was employed as the SAW/IAR of its time, while the M1919 was employed the M240G of its time; hence the terms used are relevant to the discussion.

If you look at the criteria I posted earlier of Light v Medium v Heavy, they also fit the parameters. I will add some additional criteria that I think should be fairly widely accepted;

Light – Employed by single person (BAR, SAW, IAR)
Medium – Employed by a team (M1919, M60, M240G)
Heavy – Employed by a team, but due to system/ammo weight/bulk, normally fixed or vehicle mounted (M2, M1917, Mk19)

The problem is you are placing some weapons in categories that are technically incorrect. Neither the M1918 BAR nor the M27 IAR are properly classified as light machine guns. And while the M1919 LMG could reasonably be thought of as the M240 of it's day, the M1919 was not then considered a MMG.

It'd be like calling the M1896 Krag carbine a rifle because it has a 22" barrel, longer than those of many modern military rifles.

To avoid such contradictions, I'd suggest leaving historical weapons with their original classifications, which were appropriate for their times. That's if there's even a need to include them in the discussion.

I'd also suggest that four categories are needed:

IAR
LMG
MMG
HMG

[Tony Williams]

I'd also suggest that four categories are needed:

IAR
LMG
MMG
HMG

Which raises the question of where the Bren gun would fit into that classification.

It was magazine-fed, and carried and used by one man, which would suggest it's an automatic rifle like the BAR.

OTOH, it had a quick-change barrel and the gunner usually had an assistant who would carry more ammo and also change the magazines more quickly than the gunner could - which suggests an LMG.

You can spend hours debating these sort of points, because there isn't one correct set of designations, and they are affected by how the weapon is used as well as by its characteristics.

[stanc]

You can spend hours debating these sort of points, because there isn't one correct set of designations, and they are affected by how the weapon is used as well as by its characteristics.

I'm not going to debate that. I'll just say that I disagree that there isn't one correct designation, or how the weapon is used affects its designation. The M249 is used in the automatic rifle role, but it's still a light machine gun, and the Army classifies it as an LMG.

There are a number magazine-fed weapons from years gone by which were classified back then as machine guns, not automatic rifles. There are belt-fed guns like the M1919 LMG, which today would more properly be considered a MMG. There is also a Japanese LMG (Type 11?) which was fed via rifle stripper clips, but that doesn't make it a rifle. Do we set about re-classifying all of those obsolete and obsolescent weapons to meet current standards? Or do we just let their historical designations stand, and place our attention on current and future weapons?

[JASmith]

Why don't we simply stay with Michael's definition :

...additional criteria that I think should be fairly widely accepted;

Light – Employed by single person (BAR, SAW, IAR)
Medium – Employed by a team (M1919, M60, M249G)
Heavy – Employed by a team, but due to system/ammo weight/bulk, normally fixed or vehicle mounted (M2, M1917, Mk19)

The only reason for not using this is if someone can dig up a current, authoritative Army Field Manual or Marine Corps equivalent that suggests a revision.

[Tony Williams]

Well, since you've ducked the question about the Bren gun (and various similar devices) what about the RPK and RPK-74 then? One-man operated, magazine-fed, fixed barrel (albeit heavier and longer than standard), bipod attached, closed bolt firing - and the Russians call it an LMG.

Or the STK Ultimax 100: magazine-fed and one-man operated, but fires from an open bolt, has a quick-change barrel and the usual magazine capacity is a healthy 100 rounds. That's more of an LMG than the RPK.

The fact is that there are various characteristics which might - or might not - distinguish the IAR from an LMG: characteristics of an LMG will include some (but not necessarily all) of:
- quick-change barrel,
- belt feed,
- open-bolt firing,
- permanently attached bipod,
- heavy barrel,
- sturdier construction than rifle to withstand constant automatic fire.

The problem is that different weapons use different combinations of those features, as illustrated by the examples I've given.

[stanc]

Why don't we simply stay with Michael's definition :

The only reason for not using this is if someone can dig up a current, authoritative Army Field Manual or Marine Corps equivalent that suggests a revision.

The main reason for not using it is that it's inaccurate. Even if older weapons (for example, the M1918 BAR) are left out, the M27 IAR is not a light machine gun.

[cory]

What the hell difference does it make whether it's classified as an LMG or MMG here on the forum??? I assure you the nomenclature makes no difference to the Grunts on the ground who are employing it on the battlefield or are on the receiving end of it's barrage. We're arguing the pronunciation of the word "THE".

The only difference that's relevant to this discussion is how it's tactically implemented and how much man power the platform requires.

I ask that we all check our egos at the door, otherwise a worthwhile discussion will continue to only go down the drain.

[stanc]

Well, since you've ducked the question about the Bren gun (and various similar devices)...

I didn't duck it. I attempted to address that by saying: "There are a number magazine-fed weapons from years gone by which were classified back then as machine guns, not automatic rifles." The WWI-era Madsen LMG is another example.

...what about the RPK and RPK-74 then? One-man operated, magazine-fed, fixed barrel (albeit heavier and longer than standard), bipod attached, closed bolt firing - and the Russians call it an LMG.

Actually, the English translation of "Ruchnoy Pulemyot" is "handheld machine gun," not "light machine gun."

I guess if you don't want to consider them automatic rifles, then we'll need to add an HHMG category to the list. :p

The fact is that there are various characteristics which might - or might not - distinguish the IAR from an LMG...

The problem is that different weapons use different combinations of those features, as illustrated by the examples I've given.

Nevertheless, we are still left with the irrefutable fact that the M27 IAR is -- according to the USMC -- an automatic rifle, not a machine gun.