Weapons of the World: Little Bullets (5.56) Lose Respect

Weapons of the World ^ | November 15, 2005

[holymoly]

November 15, 2005: The U.S. Army’s cancellation of the XM8 (a replacement for the M16) reflects disenchantment with the 5.56mm round, more than anything else. While the 5.56mm bullet was OK when used in an automatic weapon, it is much less useful when you have so many troops who know how to shoot, and can hit targets just as easily with single shots. In addition to better shooting skills, the troops also have much better sights, both for day and night use. It’s much more effective to fire less often, if you have troops who can do that and hit what they are shooting at with the first shot. Most American troops can.

Moreover, the 5.56mm round is less effective in urban fighting, where you often want to shoot through doors and walls. The 5.56mm round is not as effective at doing this as is the heavier 7.62mm bullet. And the troops have plenty of 7.62mm weapons available, in order to compare. There is the M240 medium machine-gun. While this 7.62mm weapon is usually mounted on vehicles, it is often taken off and used by infantry for street fighting. Lots of 1960s era 7.62mm M14 rifles have also been taken out of storage and distributed. While used mainly as sniper rifles, the snipers do other work on the battlefield as well, and the troops have been able to see that the heavier 7.62mm round does a better job of shooting through cinder block walls, and taking down bad guys with one shot. Too often, enemy troops require several 5.56mm bullets to put them out of action.

In a situation like that, it makes more sense to carry a heavier round. The question is, which one? The army has been experimenting with a 6.8mm round, but now some are demanding that the full size 7.62mm round be brought back. There are M16 type weapons that use the full size 7.62mm round (and the lower powered AK-47 7.62mm round). The new SOCOM SCAR rifle can quickly be adapted to using all of the above by swapping out the barrel and receiver. Could be that the army is going to wait and see what SOCOM decides to do.

The other big complaint about the M16 is it’s sensitivity to fine dust, as found in Iraq and, to a lesser extent, Afghanistan. This stuff causes the rifle (and the light machine-gun version, the M243), to jam. Troops have to be cleaning these weapons constantly. Another problem with the M243 is that most of the ones in service are very old, and in need of a replacement (with new M243s, or a new weapon design.) The XM8 solved much of the “dust sensitivity” problem, but part of the problem was the smaller round.

A decision on the army’s new assault rifle will probably come sooner, rather than later, because the troops fighting in Iraq and Afghanistan are making a lot of Internet noise over the issue.

[Spktyr]

Modern muzzlebrakes and other such devices can and do reduce the muzzle climb and recoil of a full auto 7.62 NATO weapon down into the managable-by-normal-people range.

[hiredhand]

Yes! Also (and I'm scratching my head HARD to remember this!) there was a 6.5mm Swedish I "think". But it never realized it's full potential because the cartridge was underpowered for what it was capable of. Back in the 1950s, shooters were building strong bolt action rifles and chambering them for this Swedish cartridge and recording performance, but they couldn't get the likes of Winchester, and Remington (and others) to notice.

[hiredhand]

That's true...but good, effective muzzle brakes are HARD on the ears! :-)

[Squantos]

6.5x55...I have a remington 700 titanium I had rebarreled in that caliber , super ultra lite, 6X fixed power glass etc ....my favorite deer rifle.

[Spktyr]

Sonic valves are SOP for SOCOM/SEALS now. Problem solved.

[SauronOfMordor]

I had a friend (Nam 69 70 vet) that told me the early rounds "tumbled" and were twice as effective as all the new stuff. Is this what you are referring to..?

From what I read, the original design had a 1-in-14-twist barrel, which gave it just marginal stability, which caused it to tumble when it hit anything, producing impressive wounding ability in the initial reports.

Then the Army demanded that it hit targets accurately at 300 yards in arctic conditions, so they had to give it more spin. Then they sent it to Nam, where its actual usage was in non-arctic conditions, at ranges generally much less than 100 yards. Rounds went right thru the enemy without tumbling, and expending most of its energy in whatever tree was behind the enemy

[yarddog]

I am sure the 6.5 Swedish Mauser or 6.5 Norwegian Krag could be loaded hotter than the old military loads but it is probably not necessary.

I bought one with the 29 inch barrel when I was 18, actually ordered it through the mail. I ordered some 160 grain fmj round nosed ammo at the same time and for that reason had to pick it up at railway express as the U.S. Mail would not ship ammo.

Those 160 grain bullets were extremely long with parallel sides and a round nose. The velocity was probably not very high because of the weight but those things would penetrate like a striped ape.

I went down to my Uncle's swamp and literally could not find a tree they would not shoot right through.

I now mostly use Lapua match which has a 144 grain pointed boat-tail @ 770 meters per second. Not a really hot load and will not penetrate as well because of the bullet shape but extraordinarily accurate.

I have probably owned a dozen 6.5 Swedish Mausers and have never run across one which was not accurate. Some are extraordinarily so.

[SauronOfMordor]

It is hard to have a close range thumper and a long range tack driver in the same package. A larger diameter bullet with more weight will give the desired results but there are so many proven performers about that I am dubious about "new" designs. The U.S. Military has conspired to develop some pretty sorry products in the way of small arms. They all cost big bucks and have not proven satisfactory.

blended metal bullets show promise. Essentially, they fragment on impact, thus expending all the energy in the target, and providing dramatic wounding in enemy troops in actual combat usage (see link above)

Unfortunately, the Army has forbidden usage by troops.

[hiredhand]

Er...about the M-16 "tumbling" rounds. This is more commonly called a "keyhole" strike, because of the keyhole shape produced on the a target as a result of the bullet tumbling during flight. NO rifle is supposed to produce keyhole strikes!

The reason the M-16 (especially the older ones) did this is because they were manufactured with excessive freebore, in order to facilitate a wide variance of manufacture's ammo. Excessive freebore (ESPECIALLY in semiauto rifles) causes the projectile to contact the lands of a barrel on a NON-CONCENTRIC axis. This causes the same effect as when you throw a football, and it goes all "wobbly". The bullet exits the bore on a less than perfect axis, and by the time it's travelled a couple of hundred yards (sometimes less), it's in a full fledged tumble.

It's a VERY bad thing to have happen as it destroys accuracy at longer distances, and renders an otherwise good weapon, ineffective and unsuitable even under good shooting conditions!

The newer A-2s, and A-3s aren't supposed to keyhole rounds. We've got a couple of Armalite A2s and they don't keyhole, but when I was active duty we used A1s that did.

My biggest gripe about our ARs is that the mechanics in their uppers are needlessly complex, and that it "craps where it eats". The tilting block, and gas piston/tube mechanism is widely used (except for with things like H&Ks blowback system), and I can't for the life of me figure out why they settled on the complex little system that the AR uses.

...having now complained about it I have to admit that a buddy of mine in an operational unit just returning from Iraq tell me that their A2s and M4s were VERY reliable and rarely malfunctioned.

[hiredhand]

SF folks are the exception. :-) Supressors would solve the problem too.

[hiredhand]

I love Mausers. :-) Every shooter ought to own at least ONE. Oooh! Lapua! GOOD stuff!

There are some 6.5 Swede Mausers right NOW down at our local gunshop! They're a little pricey ($300+). I'd love to pick one up, but I'm in trouble already for guns with my wife recently. ...don't want to disturb peace in my house any more than I have already.

[yarddog]

I don't know a whole lot about ballistics but assuming the bullets are not out of round, there are two things which contribute to stability.

The first is bullet construction. Unfortunately, the bullet which is most efficient in traveling through the air is one of the worst as far as stability. That is a pointed boat-tail.

This can be overcome by gyroscopic spinning, and it takes a fast twist to stabilize that type bullet. A tubular shaped bullet which is hollow point and hollow based is the most stable.

The reason those early 5.56 bullets would tumble after they hit was because of the bullet shape, they had a fast enough twis to stabilize the bullet but not when it hit something.

[Arioch7]

I can't argue with that!

[hiredhand]

THAT'S the round! 6.5x55mm Swedish. M-700s are NICE. I've had three. One got stolen (ARG!), I gave one to my brother in law (.30-06 ADL), and I've got an ADL chambered for .243. It's what I hunt with mostly. I LOVE the adjustable trigger! You can take ALL the overtravel out, lighten the pull weight, and break distance to a VERY sweet trigger! The newer ones even have a little access hole where you can SEE the trigger and sear overlap while you adjust it!

The first one I had (the one that was stolen) was bought used. The guy before me had adjusted the trigger and didn't seal up the screws properly and over time, the sealant (looked like nail polish to me) broke lose and the screws came loose. A buddy of mine chambered a round with the safety ON and the rifle discharged! Nobody was harmed, and I had a gunsmith friend of mine readjust it before I used it again!

Blue Loctite is my friend. :-)

[yarddog]

When I lived in Kansas, my neighbor was a dealer. He only bought maybe a dozen guns a year.

I had him order 3 Swedish Mausers for me @$60 each, he ordered 3 for himself at the same time. I still have the one which I thought was the most accurate.

[SauronOfMordor]

Umm, the Soviets went to the 5.45x39 from the 7.62x39, in order to gain the same perceived benefits of our 5.56.

But the Russian round has a hollow cavity in the top, which makes it tumble on impact. Since the cavity is inside the jacket, it's not a "hollow-point" and thus not barred by the Geneva Convention

[Squantos]

I use redneck loctite..........

rust

[hiredhand]

There is a fairly specific relationship between bullet weight, diameter, rifle twist rate, and it's ability to stabilize. You're correct about this. I've got a rifle now (a Rem M-700 .243) that can NOT stabilize bullets any heavier than 95gr! Actually, it's not that it can't, but the velocity which is required to cause stabilization can't be safely achieved! It would probably stress the rifle and create unsafe pressure conditions.

You're also correct about 5.56mm rounds tumbling because of striking something prior to their intended target! This WILL and DOES happen! The .243 would do this too if I used FMJs, but I use mostly 85gr HP/BTs and they fairly disintegrate if I strike something prior to the target. I like this because it's fairly flat where we hunt, and therefore somewhat safer.

As I remember, Eugene Stoner warned the U.S. Army Ordinance Dept. about changes that they made to "his" rifle (the "AR"). Among these were deminsional changes made to the throat of the chamber, resulting in excessive freebore, which with semi-autos is largely responsible for tumbling projectiles at a distance. :-)

[SauronOfMordor]

American soldiers don't shoot to wound, so why should their combat rifle?

The old doctrine I was taught in ROTC was that you shoot to wound. That way you take out of action not just the guy you wound, but all the people who must care for him

In current fights, a wounded enemy is abandoned by his side, and cared for by US. Thus every enemy wounded, but not killed, costs the US multiple people needed to care for the wounded enemy. And new rules preclude our doing anything to get useful intel out of him

[hiredhand]

Wow...WHAT a deal! I was a dealer back in the late 1980s and early 1990s and I bought a "Lend Lease" No. 4 Mk II Enfield for one of my sons. It was (and STILL is) in overall excellent condition. I bought the rifle, and an S&K "Instamount" scope mount with rings, and had it delivered to the house for just under $100.00. We still have it. :-)

...not quite the good deal that you got, but pretty good!