Notebook: Inside The Ammo Battle

[chieftain]

I wasn't there so I can't say; but I can say that in every AR/stuck case problem I have seen, heat was a contributing issue. One of the downsides of direct impingement is that it is more sensitive to the cycling time. As heat increases, the brass adheres to the chamber longer and extraction becomes more difficult. At some point, without a ramped up extractor, etc., you get stuck cases as the rifle tries to extract before the brass has obturated. These problems were well solved by the time the M16A1 was around; but once you start cutting barrels and gas systems, you reduce a lot of the safe zone built into the original 20" design.

I was.

Most of the rifles we had, didn’t get that many rounds out, often just one, before they would jam. Heat wasn’t a primary or even secondary issue.

I might be able to argue with you about ‘some’ of the solutions in the A1, and that’s why the A2 came out shortly after the war was over. It was supposed to solve the problems the A1 had. It was more solutions. By then my 10+ years was done and I was gone.

The primary improvements of the A2, IMNSHO, were heavy barrel, much better sights, and burst fire option in place of full auto. Except for the sight they all helped keep the rifle cooler. Getting rid of direct gas impingement would do it much more effectively. And ultimately cheaper.

The 6.8SPC profile shown was 110gr OTM. According to the profiles shown, it penetrates about 5-10cm deeper than 77gr Mk262 and penetrates the same or shallower than M855.

1 cm= 0.3937 of an inch
5cm =1.968 of an inch
10cm = 3.93701 of an inch

Okay. That is/was for one type round in the 6.8. There is the 6.5 too. I don’t know which one of the two would be better. But I do know in every test I have seen they have been “better” Than which ever cartridge the 5.56 fired. Some times marginally, sometimes substantially. but always 'better'.

It is a shame the Mk262 isn’t for general issue. So for most troops it is a moot point.

The temp stretch cavity is harder to compare; but seems to vary from about 4cm larger (compared to M855) to 1cm larger (compared to Mk262).

Exact same comments as above.

So, for an extra 5cm of penetration and 1cm of temporary cavity size (accuracy margin), you feel it is worth changing the bolt, barrel, and magazines of every rifle in the U.S. military as well as procuring new ammo to feed them all?

Hate to be repetitive but YES
A. that is not the only advantages and very little research has been done with these new cartridges. Certainly not 50 years worth. And much of the research on the 5.56 does not apply to the new cartridges.
B. The changes in platform I have recommended would improve a host of problems the present platform has and reduce platform costs over the life of the platform too.

I am not sure what that cost would be; but I would be willing to bet that if you spent the money on JDAMs and jet fuel (or modern mortar/arty rounds) instead, you would see a better return on investment body-count wise.

That kind of thinking is exactly what got us where we are today. You may be correct. Although a JDAM can’t do what a trooper with a rifle can do. Hold and control ground.

But the point of this argument from my standpoint is to reduce the number of OUR troops get killed. But you’re right, the JDAMs could quite possible kill many more folks than our troops with a better rifle system. Unfortunately the amount of collateral damage is much higher with the JDAM too.

Also note that most of the research applied to the 5.56mm (OTM rounds) is already applied to the 6.8... so I don't know that your comparison of research is apt.

Again much of the research of the 5.56NATO is not applicable to the 6.8.

What we DO KNOW is the M16 system is in fact getting more of our troops hurt, than a ’better’ system would.

I choose to improve the system. Apparently you don’t.

Fair enough.

Go figure.

Fred

 

[wideym]

The M16 system, like every other weapon on the planet is not perfect, but it does work fairly well.

The new wonder calibers like 6.8, 6.5, or .50 Beowolf are not the end-all platforms, just like the 5.56 was not the end-all caliber when it came out.

Instead of changing calibers, that money would be better spent on more weapons training and expecially more live fire excersices.

Bigger bullets don't always mean one shot drops, I've seen men hit with 7.62 and still keep coming(though not very many) and some hit with 5.56 drop like a sack of potatos.

And to those of you who do not think weapon and ammo weight do not matter need to throw on body armor, sapi plates, frags, water, first aid kit, squad radio, nvgs, minimum of 7 mags(more like 10, not including one in weapon), plus rifle with rail system, aimpoint, pac-4, and maybe a grenade launcher. Try humping that and any other squad equipment you have to carry on a street patrol in Baghdad or up the side of an Afgan moutain.

 

[Daniel_Junglist]

It involved a Special Forces raid in Ramadi in response to the bombing of the U.N. Headquarters in Baghdad back in August 2003. According to a soldier who was there, during a fierce exchange of gunfire, one insurgent was hit seven — count ‘em, seven — times in the torso by the 5.56, only to be brought down by a single shot to the head from a .45 caliber pistol

what I want to know is, where did the soldier or Marine get a .45 pistol, about 15 years after the 9mm M9 pistol was adopted?

that answer your question?

 

[armed85]

As a reloader, I feel using 75 gr. or heavier bullets in a .223 Rem. or 5.56mm NATO case is pushing the cartridge to the limit. I would feel better loading heavier bullets in a slightly larger case.

All things being equal, if the terminal ballistics of the 110 gr. 6.8mm SPC is very close to the 77 gr. 5.56mm, the case for the 6.8mm SPC is more appropriate for 75 gr. or heavier bullets.

What effect does a compressed load, meaning the bullet compresses the powder in the case, have in a military setting if any? Many loads with the 77 gr. .223 bullets are compressed loads or close due to lack of case capacity.