.338 mmg

[BluntForceTrauma]

I suppose a bullet weight of 300 grains vs. 147gr for 7.62 NATO at least doubles the ammo weight. This really says "vehicle-mounted only" to me.

John

[Tony Williams]

I suppose a bullet weight of 300 grains vs. 147gr for 7.62 NATO at least doubles the ammo weight. This really says "vehicle-mounted only" to me.

Actually it isn't quite double - the round weighs 700 grains compared with around 370-380 grains for 7.62mm.

A LWMMG plus enough ammo for one minute's continuous firing (500 rounds) weighs just under 105 lbs, whereas an M240 plus one minute (800 rounds) weighs 100 lbs. So from that perspective, there isn't much in it. It isn't too heavy to be carried in those circumstances in which the ability to reach out to well over 1000m is a real advantage.

In an ideal world we would have something like the Grendel as the standard rifle/LMG round carried by dismounted infantry, backed up by something like the 338NM MG in a support role, perhaps at platoon level.

[Tony Williams]

I want your job! (or what ever it was that gave you that opportunity)

Many are called, but few are chosen

[nincomp]

Mr. Williams,
I was going to compliment you on being a gentleman and not rubbing that in out faces...

[txgunner00]

Yea! Show off!

[Tony Williams]

Yes, I know. But I couldn't resist showing off my hat

[hellcat370]

Here's a vidoe I found while looking up info on it.
http://www.youtube.com/watch?v=_FWZA7FZW...ure=relmfu

Any idea if thier using a titanium reciever? Since its already similiar in weight to the M240, if they did the same thing Barrett did to the design, is it possible they could make it even lighter? How much lighter would polymer cased ammo be compared to brass cased with this round?

[JASmith]

Tony -- that IS a neat looking hat!

[Tony Williams]

Here's a vidoe I found while looking up info on it.
http://www.youtube.com/watch?v=_FWZA7FZW...ure=relmfu

And here's another one: [video=youtube;Klr0EXZty6s]http://www.youtube.com/watch?v=Klr0EXZty6s&NR=1&feature=endscreen[/video]

Both were taken at the same NDIA range session at which I fired it (along with scores of others).

Any idea if thier using a titanium reciever? Since its already similiar in weight to the M240, if they did the same thing Barrett did to the design, is it possible they could make it even lighter? How much lighter would polymer cased ammo be compared to brass cased with this round?

No mention of titanium. I doubt they could make it much lighter, it is already very light considering the power of the ammo.

I would expect that the typical polymer case with metal base hybrid would save around 25-30% of the ammo weight.

[hellcat370]

I'd be interested to see how the recoil and accuracy is when fired off the bipod, and also get some grunt feedback from carrying it and the ammo around for a day or two.

[Tony Williams]

Well the gun weighs no more than the M240, and one minute's worth of ammo (500 rounds) weighs about the same too (800 rounds of 7.62mm), so from that point of view there would be no difference.

Recoil and accuracy are likely to be no worse than the M240. The gun mechanism has a recoil-smoothing effect, which means it doesn't even need the soft-mount used with some M240 installations.

[txgunner00]

Interesting that the brass ejects to the side. Definitely not a beefed up M240. How does the bolt lock up? Is it a rotating design like the M60 or rocker like the M240?

[Tony Williams]

How does the bolt lock up? Is it a rotating design like the M60 or rocker like the M240?

I don't know - I never got to examine it that closely.

[stanc]

IIRC, the .338 MMG mechanism is derived from that of the XM307. Although it doesn't really answer the question, there is a closeup of the XM307 bolt operation at 1:37-1:42 in the video below.

http://www.youtube.com/watch?v=owZ4Hq8y_rs

[Tony Williams]

IIRC, the .338 MMG mechanism is derived from that of the XM307.

As I understand it, the XM307 is recoil-operated but the LWMMG is a hybrid type: basically gas-operated but with the XM307's recoil-smoothing mechanism.

[stanc]

FYI: http://www.dtic.mil/ndia/2012armaments/W...teimke.pdf

http://www.dtic.mil/ndia/2012armaments/2...ments.html

[BluntForceTrauma]

Noted in Steimke's report: "REQUIRES NEW TECHNOLOGY FOR A WEAPON/AMMO WITH M2 RANGE AT M240B WEIGHT." From this we can see that there are those who correctly understand the problem, and will perhaps also see a need for 7.62 NATO range at M4/M16 weight. The 65G is almost exactly analogous to this new .338 LWMMG.

John

[stanc]

From this we can see that there are those who correctly understand the problem, and will perhaps also see a need for 7.62 NATO range at M4/M16 weight. The 65G is almost exactly analogous to this new .338 LWMMG.

Yes, but there is one apparent (and important) difference:

GDATP did not just develop the .338 LWMMG and ammo, then hope the military would take notice.

Have there been any presentations on 6.5 Grendel at the NDIA meetings, with attendees permitted to shoot a Grendel carbine on range day?

[Tony Williams]

NDIA is certainly a good place to make the armed forces aware of what you have to offer. I understand that AUSA is too, although I've not been to that one.

[Gunwriter]

Question

How much of a difference in practical performance do you think there would be at inside 2,000 yards between
this system and an Old School Vickers with .303 MkVIIIZ or a French Hotchkiss with 8mm Lebel Balle N 232 grain MG ammo?
Both of these systems were habitually used for indirect fire out to 4,000 yards during WWI.
During the siege on Fort Vaux French MG crews cut down German reinforcements at 2-3,000 yards

No doubt the .338 cartridge will offer a huge step up. However to be fair the M240 is handicapped by a
rather mundane rifle load, M80 ball. Think how much performance could be improved by switching to
a 200 grain FMJ with a BC in the .530 range. Basically what the US Army did after WWI with the switch
from 150 grain M1906 ball to 173 grain M1 ball. The 173 grain M1 ball load was developed specifically to
address the poor reach of the M1906 150 grain .30-'06 load compared to the French 8mm Lebel Balle D
load US troops were initially issued for MG use. The Balle D load had over 1,000 yards of greater reach
when fired from MGs......

thoughts?