M-14 vs M-16 (Vietnam era)

[Ea$y-8]

I am doing some resreach on this subject, And I am wondering why US troops seemed to like the M-16 better than the M-14. I for one would have gone with the M-14. Even though it was heavy and lengthly and hard to swing around in the brush It had outstanding accuracy, wicked firepower, and did not need alot of cleaning. The M-16 however had accuracy but is infamous for it's lack of stoping power and needed a ton of cleaning. And as for the maganizes the M-14 had a 20 rounds of 7.62mm bullets the M-16 a 30 round clip of 5.56mm bullets.

[ogukuo72]

The M16 in Vietnam started out with 20-round mags, but more 5.56mm could be carried for the same amount of weight compared to the 7.62mm.

It's size and weight is probably a key factor in a Southeast Asian jungle. It is also more controllable when fired on auto. Together with more ammo on hand, this actually meant more firepower at the short ranges in a jungle.

As far as I know, the M193 5.56mm ammo used in the M16 and M16A1 does not have as bad a reputation as the M855 5.56mm in the M4 in terms of "stopping power".

The "tonnes of cleaning" phrase is unfair. It is not much more difficult to clean than other weapons, the most awkward bit being the carbon deposit on the inside of the bolt carrier. A bent-tip steel tweezer or a dentist's pick is a useful tool on hand for this.

[scrybe]

Not sure where you have been doing your research but from all of the books I have read, the vast majority of US troops in Vietnam did NOT like the M-16 immediately after the swap. Many refused to exchange their M14s for the new plastic rifles. The first M16s had issues with reliablity and many did not like the drop in knock down power from the 5.56 to the 7.62. Later models greatly reduced the issues with jamming though.

[ogukuo72]

No research on what US soldiers like, just my $0.02 worth based on my military training in the jungle.

[dangerdan87]

As far as I know, the M193 5.56mm ammo used in the M16 and M16A1 does not have as bad a reputation as the M855 5.56mm in the M4 in terms of "stopping power".

What?

The two ammo loads can be used in either or and both cause deadly internal wounds.
And the only difference is that the M195 Ball is a 5.56mm 55gr FMJ and the M855 is a 5.56mm 62gr FMJ Steel Core (steel penatrator), which usually has a green tip.

[Taekwondo]

Not sure where you have been doing your research but from all of the books I have read, the vast majority of US troops in Vietnam did NOT like the M-16 immediately after the swap. Many refused to exchange their M14s for the new plastic rifles. The first M16s had issues with reliablity and many did not like the drop in knock down power from the 5.56 to the 7.62. Later models greatly reduced the issues with jamming though.

The reliability problem was, at least partially caused by the first models' cleaning instructions - none! Or at least minimal. So the troops kept their guns the way they were, and of course they jammed ultimately. Result: bad reputation for first M-16s as jamming. The manufacturer quickly corrected the cleaning issue in the instruction manuals.

[dangerdan87]

The only usless and not-so-reliable thing on the M14 was the full-auto selection....

M14 FULL AUTO DATA
1st shot: Dead on
2nd shot: Squirrel hunting
3rd: shot: Anti-Aricraft
And so on.

[flanker7]

As far as I know, the M193 5.56mm ammo used in the M16 and M16A1 does not have as bad a reputation as the M855 5.56mm in the M4 in terms of "stopping power".

What?

The two ammo loads can be used in either or and both cause deadly internal wounds.
And the only difference is that the M195 Ball is a 5.56mm 55gr FMJ and the M855 is a 5.56mm 62gr FMJ Steel Core (steel penatrator), which usually has a green tip.

The M855 can be fired from an A1 barrel but the M193 doesnt stabilize in the A2 barrel. The problem with the 5,56 lethality is that is depentent on speed. Especially the M855. There's a "critical" speed beneath which the round does not fragment and remains stable inside the target. When fired from the M-4 this critical speed is reached at a very small range. In any case the M193 round was more leathal at close ranges due to its higher speed. The M855 is better at longer ranges because it retains speed more due to it's higher weight. This advantage is lost however when fired from short barrels :|
That's offcourse my opinion :)

[muede]

The M-16 however had accuracy but is infamous for it's lack of stoping power and needed a ton of cleaning.
What Vietnam era M16 is infamous for is the fact that if one was shot the the chest, hed be missing fist size bits of flesh in his back on the exit wounds, and also the wound channels it made as a whole were quite impressive..

So lack of stoping power wasnt a issue imho, but it had severe issues in penetrating any obsticles in its path, even very small ones sticks and such had a habbit of braking the bullet up or deflecting it..

[ogukuo72]

There is major discrepencies between different accounts on the effectiveness of the 5.56mm rounds. It might have something to do with the depth of penetration before yawing.

If the angle and depth of penetration is such that the 5.56mm bullet do not have time to yaw and fragment, the wounding effect might be small. A hit to the arm or leg (without breaking bone or cutting arteries) could cause very minor wounds. At the same time, a hit in the torso, could cause more massive injury.

The supposedly better wounding effect of the M193 round could be down to the bullet yawing earlier when compared to the M855 round. I can only confirm this tonight when I refer to some material.

BTW, although we do not hear of this often, the 7.62mm round would also be subject to the same wounding mechanics. Indeed, if I remember correctly, it might even be that the 7.62mm yaw after a much deeper penetration. Of course, it would compensate for a lack of yawing by a larger diameter wound channel.

[Retard]

The M855 can be fired from an A1 barrel but the M193 doesnt stabilize in the A2 barrel.

I believe you have that you backwards. The A1 has a 1-12" twist & the A2 has a 1-7" twist. The A1 has problems stabilizing the longer 62 gr. M855.

I fire M193 through A2's & M4's without a problem. I typically get 1.5-2 MOA with the M193 through a A2 & 3 MOA through a M4. I fired the M855 through a M16A1 only once. It grouped better than I thought (4 MOA), but some of the holes in the target were elongated.

It more complicated than this, but the main factor with the 5.56mm current problem is velocity. We went from:
M16A1 firing a M193 cartridge at 3250 fps
to the M16A2 firing the M855 at 3100 fps
to the M4 firing the M855 at 2900 fps.

[flanker7]

I wont argue because I wrote it from memory. You're propably right. I thought they changed the rifling in order to stabilize the longer Tracer round.

[Retard]

I thought they changed the rifling in order to stabilize the longer Tracer round.

You are correct the the 1-7" was choosen due to the tracer round. Most feel the the 1-9" twist is the best twist for the M855.

http://www.ammo-oracle.com/images/rounds3.jpg
Left to Right: M193, M855, M856, Sierra MatchKing HPBT

Excellent 5.56mm info at :
http://www.ammo-oracle.com/

Here's some sections:
Q. OK, what is all this stuff about rifle twists and different ammo?

Rounds in flight spin for stability because of the rifling on the inside of the barrel. Depending on how much they spin, they are more or less stable in their flight and therefore more or less accurate. The earliest AR15s from the early 1960s had a twist rate of 1 complete twist every 14", or 1:14. This was increased to a twist rate of 1 turn in 12" for the M16, XM16E1, M16A1, and later rifles and carbines. The current M16A2s and up and the M4 carbines have a much faster twist rate, 1 turn in 7". The reason for the 1:7 twist is mainly to stabilize the M856 tracer bullet, which is much longer than other bullets. You will recall from above that the M856 was designed to provide 800 meters of trace out of the SAW.

While the slow 1 in 12" twist is adequate to stabilize the 55 grain M193, it will not stabilize the 62 grain M855. As a result, the newer M855 ammo will group 1-2 feet at 100 yards, with bullets flying through the air sideways, instead of shooting to about 2" at 100 yards, like military ammo should.

All this has some ramifications for ammunition selection depending on your rifle's rate of twist.

You can also overspin projectiles and cause overstability. This results in the not-so-desirable condition that keeps the nose of the round pointed high, as illustrated below:

http://www.ammo-oracle.com/images/overstable.jpg

You can also spin them so hard they fly apart. That's rare, but it happens if you are dealing with very tight twists and very high velocities. When fired at 3200 fps in a 1-in-7 twist rifle, a round is rotating at over 300,000 rpm when it leaves the muzzle. Light, thin-jacketed varmint bullets (i.e., 40gr Hornady TNT or Federal Blitz bullets) often can't take that much spin and will pull themselves apart.

Fact: Generally you want a gyroscopic stability factor (Sg) of 1.3 or greater in a given round, about the low end for normal shooting. You get this on the larger M855 round with a 1 in 9" twist. By comparison a 1 in 10" twist will keep that M855 round down to about 1.2- not enough if it starts to get cold. Really you want stability to be between 1.5 and 2.0- a 1 in 8" twist on a M855 round. In actuality a 9" twist is a bit better for accuracy as it doesn't spin up non-balanced bullets too fast causing them to wobble in flight. If you have match rounds, well balanced and tested, you don't really have to worry about overtwisting until you hit 5.0 or so.

http://www.ammo-oracle.com/images/target2.jpg
The result of unstabilized bullets:
A 1 in 12" FN-FNC firing M855 at 100 yards.
(Note the profiles cut out of the target).

Math and Physics: A spin-stabilized projectile is said to be gyroscopically stable, if, in the presence of a yaw angle, it responds to an external wind force with the general motion of nutation and precession. In this case the longitudinal axis of the bullet moves into a direction perpendicular to the direction of the wind force.

It can be shown by a mathematical treatment that this condition is fulfilled, if the gyroscopic stability factor (SG) exceeds unity. This demand is called the gyroscopic stability condition. A bullet can be made gyroscopically stable by sufficiently spinning it.

As the spin rate decreases more slowly than the velocity, the gyroscopic stability factor, at least close to the muzzle, continuously increases. Thus, if a bullet is gyroscopically stable at the muzzle, it will be gyroscopically stable for the rest of its flight.

Q. OK, that's complex. Simple question: Can I fire M193 ammo in my 1:7 or 1:9 twist barrel?

Yes.

M193 is essentially a "universal" round; able to be stabilized by barrels with twists between 1:14 and 1:7. Point of impact will change slightly compared to an M855 zero, so rezeroing is recommended.
Fact: The Scoop from the Army's Ammunition Information Notice (61-01) "INTERCHANGEABILITY OF 5.56MM BALL, TRACER AND BLANK AMMUNITION."
It is acceptable to use M193 and M196 ammunition in training in M16A2, M16A3 rifles and M4 and M4A1 carbines (16 percent range reduction). Substituting between types of ammunition during firing is not recommended.

Q. Can I fire M855/SS-109 in my 1:12 twist barrel?

Yes, but...

...it won't be stabilized properly and after 90-95 yards, it will typically veer off in a random direction. You often won't hit paper at 100 yards. Though it won't hurt your rifle to fire this ammo, it is not recommended. Military manuals warn that it should only be fired in 1:12 twist barrels in a "combat emergency."

Q. Will M193 be accurate in a 1:7 or 1:9 twist barrel?

It may be marginally less accurate due to the fast twist rate, particularly in 1:7 twist barrels. Unless you're trying to use these rounds for benchrest shooting, though, it shouldn't be enough to matter.

A bullet's flight is disrupted slightly as it leaves the barrel and after traveling some distance, will "settle down" into an even spiral, similar to a thrown football. The faster a bullet is spinning, the longer it takes to settle down. The most accurate twist rate for any length of bullet will be just a bit faster than what is required to stabilize it for its entire flight path (1.3 SG). But note that bullet quality plays a much bigger part in this equation. A uniform bullet will spin true; a non-uniform bullet will wobble and be inaccurate. As a general matter when shooting M193 or M855 (as opposed to match ammo) its better to err on the side of a faster twist rate. Regardless, both 1:9 and 1:7 twists seem to shoot M193 and M855 very well.
Q. What twist rate do I want for my rifle?

Probably 1:9, but it depends on what kind of bullets you intend to shoot.

Special purpose rifles often have uncommon twist rates. For example, if you are building a varmint rifle and want to shoot the short 35 grain, 40 grain, and 50 grain bullets, a 1:12, or even 1:14 twist would be best. On the other hand, long range High Power shooters often select 1:8, 1:7.7, 1:7, or 1:6.5-twist barrels to stabilize the long 77, 80 and even 90 grain bullets used for 1,000 yard competition. Additionally, new testing of heavier rounds (68-77 grains) seems to show that they perform very well in simulated tissue and may be a better defensive choice than 55 grain or 62 grain rounds. The majority of shooters, though, typically shoot bullets of 50 to 69 grains in weight (note that the 62gr SS-109/M855 bullet is as long as a 71 grain lead core bullet) and should select 1:9 twist barrels. At typical .223 velocities, a 1:9 twist will stabilize bullet lengths equivalent to lead-core bullets of 40 to 73 grains in weight.

1:12 twist rifles cannot stabilize SS-109/M855 bullets and 1:7 twist rifles are slightly less accurate with lighter bullets and will often blow apart the thin jackets of lightweight varmint bullets. The 1:7 twist is used by the military to stabilize the super-long L-110/M856 tracer bullet out to 800 yards, but unless your plans include shooting a significant amount of M856, the 1:9 twist rate is better suited for general use.

There is, of course, an exception: if you want to use loads utilizing the heavier, 75-77 grain match bullets currently used by Spec-Ops troops and other selected shooters, you'll want a 1:7 twist barrel. Although military loadings using these bullets are expensive and hard to get, some persistent folks have managed to obtain a supply, and will need the proper barrel twist to use them. Anyone who foresees a need to shoot this ammo should consider a 1:7 twist barrel.

[ogukuo72]

Thanks! This is very informative. :)

If only we can keep debates about such things to such exchange of informations, rather than just exchange of opinions and hearsay. (I'm plenty guilty of the latter, I must say!) :P

[flanker7]

So, I was right the first time? Never mind. The 1/ 9" is the one used on the SAR21? I also heard that this rifling will stabilize both rounds fair enough

[XASA]

I was issued an M-14 in basic and for my entire three year stint in Berlin before being trained on the M-16 and issued one my last two years in the Army (FYI: Berlin Brigade was the last Army unit to carry M-14s and did so well into the 1970s; it was also the last unit to be issued the 90mm RR).

The M-14 was deadly accurate at long range and I shot expert four years running with one. Most were issued without a selector switch and could shoot semi-automatic only. Carrying extra ammo wasn't an issue-- we figured if our fathers and uncles could carry an M-1 and a basic combat load of 160 to 240 rounds in WWII, we could manage five 20 round magazines that were our basic load.

The The M-16 although lighter and capable of automatic fire wasn't nearly as accurate. As already mentioned, it had to be cleaned regularly. The problem with misfires had been corrected by the time I was issued mine and were the result of not only improper cleaning but using the wrong powder in the cartdriges.

IMHO, those who were trained on the M-14 first, liked it and preferred it over the M-16; those who never fired a M-14 and were issued a M-16 from the git go, and were properly trained in its maintenance, didn't have a problem with it after the initial bugs were ironed out.

[muede]

IIRC, the M193 started to make those extreme wounds after 10-11cm of bone and flesh.. read this from "ancient" SIPRI report. p-)

[Laconian]

I was issued an M-14 in basic and for my entire three year stint in Berlin before being trained on the M-16 and issued one my last two years in the Army (FYI: Berlin Brigade was the last Army unit to carry M-14s and did so well into the 1970s; it was also the last unit to be issued the 90mm RR).

The M-14 was deadly accurate at long range and I shot expert four years running with one. Most were issued without a selector switch and could shoot semi-automatic only. Carrying extra ammo wasn't an issue-- we figured if our fathers and uncles could carry an M-1 and a basic combat load of 160 to 240 rounds in WWII, we could manage five 20 round magazines that were our basic load.

The The M-16 although lighter and capable of automatic fire wasn't nearly as accurate. As already mentioned, it had to be cleaned regularly. The problem with misfires had been corrected by the time I was issued mine and were the result of not only improper cleaning but using the wrong powder in the cartdriges.

IMHO, those who were trained on the M-14 first, liked it and preferred it over the M-16; those who never fired a M-14 and were issued a M-16 from the git go, and were properly trained in its maintenance, didn't have a problem with it after the initial bugs were ironed out.

I was issued an M14 at USMA (no firing pin), carried it for drill, etc. but shot it at museum range days. I humped all over the woods (without a basic load). It was heavy. For markmanship purposes, I qualled on the M16. I liked the lightness of the M16, especially on road marches.

From talking to guys who were in RVN when the switch was made, XASA is right. Those that had the M14, missed it and cursed the M16 as a POS. Several guys told me they carried cleaning rods 100mph-taped to the handguards to clear jams. This was cleared up after the forward assist was added and the ammo changed. They also said they liked having full-auto on the M16 as opposed to semi on the M14.

I've also talked to a lot of WWII & Korea vets, that said they switched from their M1's to Carbines (especially when they could scrounge a full-auto one) because they were lighter, shorter, and they could carry more ammo. Soldiers will always try to lighten their load.

[Pook2]

I'll give my input from what I know and have heard. Here at VMI we are issued M14's for general duties. It's a good rifle and yes it is heavy, especially during rifle runs and forced marches carrying it at port arms, and it's worse during rifle PT. In ROTC classes we use the M16A2, I prefer the M16A2 just cause it's lighter and doesnt require a lot of effort to dissamble.


My dad's cousin was 5th SFG in Vietnam from '64-'66 I believe. He mostly used an M1A1 carbine and did not like it as much as the M16 he got. He told me the M16 was actually more more reliable than his carbine, and he also said that when he hit someone, he knew they were probably going to die. But thats just one opinion. The reliability of the M16 probably varied with every serial number and depended on how well you cleaned it.

[dangerdan87]

The problem with the 5,56 lethality is that is depentent on speed. Especially the M855. There's a "critical" speed beneath which the round does not fragment and remains stable inside the target. When fired from the M-4 this critical speed is reached at a very small range. In any case the M193 round was more leathal at close ranges due to its higher speed. The M855 is better at longer ranges because it retains speed more due to it's higher weight. This advantage is lost however when fired from short barrels :|
That's offcourse my opinion :)

Lethality doesn't depend mearly on speed. A .223 and a 5.56 bullet, on impact, will fragment and yaw making a cavity in the subject. Of course, it depends on where you hit the subject. If you aiming to kill, both the .223 and the 5.56 rounds will cause a mortal wound.

[dangerdan87]

And heres a helpful link to all your ammo Q's ... www.ammo-oracle.com

Thought that might be helpful.


Both the M14/M1A's and the NEWER styled M16/AR15's are great pieces of weaponry.

[LthrnckZero]

Check out this two-part series on the M-16 in Vietnam which explains some of the early issues, including the practice of taping cleaning rods to the weapons as told by Laconian. The article is rather lengthy but it is very informative.
http://www.jouster.com/articles30m1/index.html

[FallenAngel]

The problem with the 5,56 lethality is that is depentent on speed. Especially the M855. There's a "critical" speed beneath which the round does not fragment and remains stable inside the target. When fired from the M-4 this critical speed is reached at a very small range. In any case the M193 round was more leathal at close ranges due to its higher speed. The M855 is better at longer ranges because it retains speed more due to it's higher weight. This advantage is lost however when fired from short barrels :|
That's offcourse my opinion :)

Lethality doesn't depend mearly on speed. A .223 and a 5.56 bullet, on impact, will fragment and yaw making a cavity in the subject. Of course, it depends on where you hit the subject. If you aiming to kill, both the .223 and the 5.56 rounds will cause a mortal wound.

uhh......isnt .223 and 5.56 the same thing? (one is caliber, the other mm respectively) p-)

[Frens]

The problem with the 5,56 lethality is that is depentent on speed. Especially the M855. There's a "critical" speed beneath which the round does not fragment and remains stable inside the target. When fired from the M-4 this critical speed is reached at a very small range. In any case the M193 round was more leathal at close ranges due to its higher speed. The M855 is better at longer ranges because it retains speed more due to it's higher weight. This advantage is lost however when fired from short barrels :|
That's offcourse my opinion :)

Lethality doesn't depend mearly on speed. A .223 and a 5.56 bullet, on impact, will fragment and yaw making a cavity in the subject. Of course, it depends on where you hit the subject. If you aiming to kill, both the .223 and the 5.56 rounds will cause a mortal wound.

uhh......isnt .223 and 5.56 the same thing? (one is caliber, the other mm respectively) p-)

http://www.ammo-oracle.com/body.htm#diff

[HoboWithAK]

I am doing some resreach on this subject, And I am wondering why US troops seemed to like the M-16 better than the M-14. I for one would have gone with the M-14. Even though it was heavy and lengthly and hard to swing around in the brush It had outstanding accuracy, wicked firepower, and did not need alot of cleaning. The M-16 however had accuracy but is infamous for it's lack of stoping power and needed a ton of cleaning. And as for the maganizes the M-14 had a 20 rounds of 7.62mm bullets the M-16 a 30 round clip of 5.56mm bullets.

Do you have any firsthand experience with the lack of stopping power of the early 556 rounds? I think it's more like "I shot three entire magazines into the brush at a VC squad I couldn't even see, and when they left we went in to confirm the dead we found only one spat of blood and no bodies, therefor the round is underpowered" than "the round is underpowered".

My uncle was shot down several times as a UH-1 gunship pilot, and every time his little survival .38 and his M16 saved his ass in the bush. He never told me about it being underpowered- if anything, he liked it's ability to hold more of the smaller rounds.

By the way, it's magazine, not clip. And rounds or cartridges, not bullets.

[Daga]

There is still new production m193 in the supply system - we use it regularly for qualifications (m16a2 rifles ie 1:7 rifling for Army ROTC) - no problems.

[Delta Niner]

Not sure where you have been doing your research but from all of the books I have read, the vast majority of US troops in Vietnam did NOT like the M-16 immediately after the swap. Many refused to exchange their M14s for the new plastic rifles. The first M16s had issues with reliablity and many did not like the drop in knock down power from the 5.56 to the 7.62. Later models greatly reduced the issues with jamming though.

I tend to agree with what Scrybe has said, the M-14 the preferred weapon of the US soldier at that time. IMHO the constant jamming during the first phase of the issuance of the M-16 was due to the failure of the US Army to adapt the IMR (Improved Military Rifle) round that Eugene Stoner had endorsed. With regards to the constant cleaning. We are talking about minute parts here for the M-16 compared to the M-14. Which is easily fouled by the non usage of the IMR rounds. :)

[andreen]

I dont know that mutch about the inside storys of vietnam, but can it be that some units liked the M14 or the M16 depending on what they did and what their task was. M14 for more urban combat and the M16 if you walk in the jungle for a long time.

Just a thought

[ogukuo72]

Could be. I think the Marines used their M-14 for far longer than their army counterparts.

But I doubt that the M-14 would be preferred for urban warfare. The M-16, with its smaller size, lighter weight and automatic fire, would be the preferred firearm during house clearing. It would also be the preferred firearm in the jungle, for the same reasons.

In terms of Vietnam, the terrain that most favour the use of the M-14 would be the cultivated regions in the lowlands.

[Mark Sman]

The basic SNAFU with the M-16 release breaks down into several parts.

Eugene Stoner designed a rifle based around a very specific 5.56 cartridge he was given. It worked.

The DoD changed the powder of the cartridge after he designed it. Oops.

Also, initial issues of the M-16 had neither a chromed chamber, or a foward assist.

Lack of a foward assist was a design flaw. Not having the chromed chamber was a problem in the humidity of Vietnam under combat conditions. Example: A brass case from a cartridge sits in a steel chamber for 12 or more hours of duty while semi-wet. Bad juju in the long run.

The powder switch would not have been an issue if it had been taken into account during development. As it later was.

These issues were cleared up relatively quickly, but it left behind half-truths and scary rumors that followed the rifle for years.

The M-14 is a great rifle, but the disparity in ammunition weight becomes very evident when dealing with larger amounts. Remember it isn't just the soldier that has to hump the rounds. How many rounds can you load on a chopper? A truck? Two very different numbers.

[Yankee_Delta]

in SE Asia i would definatly pick an M16
as for stopping power-double tap

if i had a choice id take an M1A Scout Squad with me to WW3

[Vympel]

i preffer m 14... powerfull and reliable

[Chops]

in SE Asia i would definatly pick an M16
as for stopping power-double tap

*lol*

*lol* you're a ****wit *lol*

Stop dredging up threads from 2000 and ****ing 5 to add your imbecilic five cents. Moron.

Same goes for you Vympel

[Red]

*lol* you're a ****wit *lol*

Stop dredging up threads from 2000 and ****ing 5 to add your imbecilic five cents. Moron.

Same goes for you Vympel
Your avatar gives me the willies.

[H2O MAN]

I am doing some resreach on this subject, And I am wondering why US troops seemed to like the M-16 better than the M-14.

Where did you hear that?

[3rdMillhouse]

The reliability problem was, at least partially caused by the first models' cleaning instructions - none! Or at least minimal. So the troops kept their guns the way they were, and of course they jammed ultimately. Result: bad reputation for first M-16s as jamming. The manufacturer quickly corrected the cleaning issue in the instruction manuals.

I also heard that, initially, there were some problems with the quality of gunpowder used in the first 5.56mm amunition issued to the troops. Am I right?

[California Joe]

Um yes...I'm pretty sure if you actually read the thread someone mentions it. Mmmmkay?

[Limeyfellow]

Could be. I think the Marines used their M-14 for far longer than their army counterparts.

But I doubt that the M-14 would be preferred for urban warfare. The M-16, with its smaller size, lighter weight and automatic fire, would be the preferred firearm during house clearing. It would also be the preferred firearm in the jungle, for the same reasons.

In terms of Vietnam, the terrain that most favour the use of the M-14 would be the cultivated regions in the lowlands.

The Marines used the M14 for far longer, because for many decades they had to do with the Army's cast offs. They got the M1 Garand last, they got to use the older webbing for longer in Korea and Vietnam, the older helmet when they switch to the M1 helmets and so on. That has changed nowadays, but for about a hundred years this was true.

[11 Bravo]

I believe you have that you backwards. The A1 has a 1-12" twist & the A2 has a 1-7" twist. The A1 has problems stabilizing the longer 62 gr. M855.

I fire M193 through A2's & M4's without a problem. I typically get 1.5-2 MOA with the M193 through a A2 & 3 MOA through a M4. I fired the M855 through a M16A1 only once. It grouped better than I thought (4 MOA), but some of the holes in the target were elongated.

It more complicated than this, but the main factor with the 5.56mm current problem is velocity. We went from:
M16A1 firing a M193 cartridge at 3250 fps
to the M16A2 firing the M855 at 3100 fps
to the M4 firing the M855 at 2900 fps.



Maybe you have the compromise 1-9" twist ?. I won alot of bets when on the live fire ranges when using M855 in A1's and M193 in A2's...... groups were horrendous and keyholing was commonplace on both with the wrong bullet.
I work with a guy whom has a spanking new civilian version of the A2 and he could not get it to make a group for love or money. Turned out he did not know the difference between the M855 and M193 cartridges. I had a couople 7,62 cans of loose M855 ball and M856 tracer so I gave him a couple hundred rounds. Don't you know he can actually hit the target with tight groups now.
The first batches of M16's procured and sent to vietnam had a load of problems that they should never been allowed to have like dropping the chrome bolts and carriers , and chromed chambers. Oh and lets not forget the ammo scandal in that older and very improper burn rate ball powder was used by the contracted manufacturers for M193 ball which were the root cause the vast majority of stoppages in the field. As well the mullet was slightly reconfigured without consult or known lessening effect of lethality.
Original M193 ball bullets have a very pointed nose , later manufactured M193 bullets have a very noticeably blunted point nose.
I do beg to differ on the M193 in the regards that the velocity of it and it's ogive design tend to make it turn turtle in soft matter really freakin' quick on impact. I have revovered spent M193 bullets from deer carcasses down to clay like mud and never encountered any severe over penetration , but found universally that the bullet turned turtle and it's exposed base then expanded akin to a hoolow pointed bullet I have found a fair amount of intact M855 bullets in mud and clean in out penetrations in deer. I still have the AR I bought way back in '85...and I love what it and M193 ball can do.
From what my friends that have been to A'stan and the sandbox tell me the M4 with it's shorter barrel and the slower less lethal M855 ball loading coupled with it make for a fairly ineffective manstopper at pretty much anything but dead nuts range.
Of the troops in Vietnam , their dislike from the get go was most had neevr seen or handled an M16 when they were handed one. A soldier being familiar with his rifle makes for effective soldiering. So such a mandated swap with the mentioned deficiencies made for a disaster , whcih really was straightened out qucikly as these things go.