Sgt. Clifton "Corky" Cathcart.
Combat mission Vietnam 1968.
The M16-A1 weapons system.

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M16-A1 Weapons System
Loss of design intent!

The M16‑A1 was not referred to as a rifle or just a weapon, but as a weapons system; because, that is what it was. Very important: The "M16‑A1 Weapons System" consisted of "both" the rifle and the very special 5.56 caliber 55 grain bulleted ball ammunition. (The 5.56 ammunition used "ball powder." And, even though the 5.56 ammo looked identical, it was "very" different from .223 caliber ammunition.) The rifle and ammunition were designed as a matched set and were designated as such. Hence, the designation "M16-A1 Weapons System."

The M16 rifle was conceived to provide the U.S. infantryman with a new and very special weapon. In some cases, as in Vietnam, the soldier needed to be able to carry a load on his back that could sustain him in combat for 3 days without resupply. That meant everything he carried on his back (food, weapon, ammunition, sleeping gear, clothing, water etc.) had to total a manageable weight. In previous wars, they conventionally would establish a beachhead, and then a "front line" that pushed forward from that stronghold. In theory, then, everything behind that front line was safe and resupply lines could flow continuously from the beachhead. That meant rifle and ammunition weight was not so important as was the weapons effectiveness in stopping enemy combatants. The M-1 and M-14 that preceded the M-16 would stop an elephant dead in its tracks, but, they were heavy.

The military somehow settled on about 400 rounds of ammunition as being sufficient as a basic load for the individual soldier to carry when isolated as part of a small group. If he was careful at all, he should be able to remain in combat for 3 days with that amount of ammunition. One big problem they faced in their new type war in Vietnam was thus the weight of the ammunition as well as the rifle. The M‑14 rifle the M16‑A1 was designed to replace was a big bore high power weapon. With 400 rounds of ammunition loaded in magazines, the M‑14 weighed in at well over 70 pounds. Way too much for a soldier to carry along with his other basic needs!

Diz, Wayne Bratz [KIA], Jim Spearman
These real life combat soldiers in full battle gear demonstrate the military's need for the new M16. In first deployment, the weapon that would become the M16‑A1 was provided in .223 caliber. The new rifle with 400 rounds of ammunition in magazines weighed barely over 20 pounds. That, even combined with a soldiers other gear, produced a heavy but manageable load. The .223 was a relatively new hunting round and even though it's diameter and bullet weight was low, it was effective because of it's extreme velocity. The military found that while the .223 was effective to kill enemy combatants [or as we see in today's world, cowards using them to kill school children], the .223 proved ineffective at "stopping" true zealots on first strike impact. If it takes an enemy soldier one minute to die from being shot, that may well be time to kill you and maybe all your friends. Eugene Stoner, who is largely credited with the design of the M16‑A1 weapons system, came up with a brilliant and simple solution that both preserved the early M16 design [in .223 caliber] and gave it much more stopping power. Stoner and his team concluded the little .223 55 grain bullet needed more velocity [and thus more energy to transfer] to become an effective battlefield weapon. As you think about the difference between the [identical looking] .223 and 5.56 ammunition, remember, the sole reason of the new 5.56 nomenclature was to increase the battlefield "stopping power" of the ineffective .223 designation. Don't be fooled, then, to be among so many who imagine and believe they were the same round. To now say the 2.23 and 5.56 rounds are the same is to credit Mr. Stoner and his design team with being incompetent; with being fools really. They were not! The designers settled on a solution consisting of the only slightly modified 5.56 caliber rifle and the very special 5.56 ammunition combination.

[Available as background to help Mr. Stoner and his team: The military had only recently developed the M-18 Claymore Mine. The Claymore is a little plastic enclosed device slightly smaller than a license plate and a bit over an inch thick. It's plastic case contains a nearly 1 inch thick slab of C4 plastic explosive, covered with a layer of 700 roughly 1/8 inch diameter ball bearing like pellets on the "front" side of the layer of plastic explosive. The Claymore is a directional, command detonated, anti-personnel mine. The soldier simply points the device toward the enemy, moves away from behind it, and detonates it... What the military had learned from the research and development of the Claymore largely impacted the 5.56 weapons system development; because, well, they really had the same problem. The Claymore designers discovered that, even using those tiny 1/8 inch diameter pellets, if they could get their velocity up to about 4000 feet per second (fps), the tiny pellets became a formidable weapon. Increasing velocity of a projectile, of course, increases energy to be transferred to target. Nearing 4000 fps, however, they learned the method of transfer becomes different. Nearing 4000 fps, the projectile nearly explodes (fragments) on impact with the target, even with soft tissue, thus transferring most all the energy to that point of contact. Having knowledge of what the military had learned from the claymore development, then, Stoner applied it to the M16-A1.]

Armed with the "velocity" knowledge the military had gleaned from Claymore mine development, Mr. Stoner and his team developed the brand new M16‑A1 5.56 chambered rifle; with its matched 5.56 caliber 55 grain bulleted ammunition. Their new ammunition looked just like a .223 round but there was some danger inherent in that similarity. The .556 ammunition was very different, and even though it would fit, it could not be fired safely in a .223 chambered weapon. To be able to use the new ammunition, they strengthened [using different materials] and slightly altered the chamber of the M16‑A1 rifle by machining forward bullet clearance, allowing the short and light 55 grain bullet to move forward about 1/4 inch before it contacted the rifling in the barrel. That meant it took very little chamber pressure to move the 5.56 bullet that first 1/4 inch. Then, they loaded the M16‑A1 5.56 ammunition with a lot more powder [or a powder designed to produce a lot more pressure] than the .223 ammunition. In my layman's understanding, what that all accomplished was this: As the powder ignited, the 5.56 bullet started to move forward at very low chamber pressure against almost no resistance. That 1/4 inch free movement clearance, along with the short 55 grain bullet, provided extra space for the expanding gas in the 5.56 chamber. The barrel rifling used a low twist rate of 1 in 12 inches. So, once the 5.56 bullet was in motion, it would easily continue in motion without added resistance from a greater twist rate in the bore. All that, along with the 20 inch long barrel, allowed for chamber pressure to ramp up slower but to continue to increase [or at least to continue high] behind the bullet until it exited the barrel. The whole point of their modified design was to achieve maximum velocity [and thus maximize stopping power] in the 5.56 M16‑A1 projectile. Their well thought out changes completely altered the pressure curve in the 5.56 chamber, such that they had to measure the pressure from a different port location than had been used with the .223. While I didn't know the details of how they accomplished that velocity increase when I was using the rifle in The Nam, I was told the M16‑A1's we used were firing at near 4000 feet per second. Being a hunter, I had some idea what that meant. That's at least a 25 - 30 percent energy increase in the 5.56 bullet over the .223 caliber. I can still remember the feel of my A1 when fired. When I fire a modern 5.56 AR-15, using modern 5.56 ammunition and even with the 20 inch 1 in 12 twist barrel, it doesn't even feel like the Vietnam era M16‑A1. That M16‑A1 weapons system would empty an 18 round magazine [20 round mags loaded minus 2 for reliability] in under one second. When firing a single round, it banged and recoiled slightly and was just ready to fire again. There was no perception of the mechanics inside the weapon as it ejected and re-chambered. Firing modern 5.56 ammunition makes it feel like holding a thrashing machine to your cheek. Mr. Stoner and his team solved the problems the military had with ice pick wounds produced by the .223, and with the weapon not putting an enemy combatant down with one hit. M16‑A1 weapons systems were effective. None of us ever had to think about shooting an enemy soldier 3 times to stop him.

The M16‑A1 weapons system was so effective several nations have adopted cloned similar caliber weapons. Sadly, however, it seems the M16‑A1 weapons system design intent has been lost to U.S. military and their allies. Well meaning but ignorant [of understanding the original design intent] men came along believing they could make "improvements." They though one improvement would be longer and heavier 62 grain bullets. That modification reduced chamber expansion space, which forced the use of less powder, which lowered velocity even more than it was already lowered just by the extra bullet weight. That lowered velocity, in turn, lowered bullet rotational speed; and so introduced bullet stabilization problems. Trying to stabilize the heavier 62 grain bullets, they increased the barrel twist rate which again lowered velocity, and produced less energy for transfer to target. Next, feeling the need for a shorter "handier" rifle, they cut 4 inches off the barrel; again lowering velocity. If they wanted a shorter weapon, they should have used one of the successful .556 "Bullpup" designs and kept the 20 inch barrel. Finalizing their neutering of the M16‑A1 weapons system, they actually stopped producing the M16‑A1 5.56 high velocity 55 grain ammunition. By all those modifications, they effectively detuned the M16‑A1 back down to its original .223 caliber status. They essentially undid everything Stoner's team accomplished. The U.S. Marines did keep the 20 inch barrel for a lot of years, but I think even they lost the high velocity M16‑A1 weapons system 55 grain ammunition. Now, we hear soldiers complain about their weapons producing ice pick wounds and the need to "triple tap" a target. For a period, they even put in a 3 round burst mode to enable soldiers to do just that. At that point, the benefit of the light weight of the weapon and its ammunition was completely lost. What would be the benefit of carrying ammunition that is 1/3 the weight of the M‑14 ammo, if you have to shoot a combatant 3 times to stop him? Modern M16 ammunition variants are labeled 5.56, but they really only perform to .223 caliber specs. Many people even fire modern 5.56 ammo in weapons chambered for .223. That would prove catastrophic with true M16‑A1 weapons system ammunition. The ammunition we fired in Vietnam would greatly over-stress a .223 chambered weapon. Never fire 5.56 ammunition in a weapon chambered for .223. You might get hold of a real 5.56 specked cartridge. It is my understanding the M16 got a bad reputation early on in Vietnam because someone ignorantly issued M16‑A1 weapons system 5.56 ammunition to troops still carrying some of the early .223 chambered rifles; that with disastrous consequences.

In this life I have lived, I am proud of the men I served in Vietnam with. I am proud of my own service alongside them. We had a saying in Vietnam: "Speak softly and carry a little black stick." The M16‑A1 weapons system was a tool my life depended on. I had one in my hand or at arms length for a year of my life. It just troubles me that what the M16‑A1 once was has been forgotten and my nation's troops in our day are armed with what amounts to the old .223 weapon Mr. Stoner and his team felt was ineffective for the battlefield...

Enough talk, though, about this old world system (1 Johe 5:19) and the methods we have used to kill each other. (Isa 2:2-4) I am thrilled to have traded in my "little black stick" for the complete suit of armor from God; including the only truly perfect weapon, the sword of the Spirit [which is God's Word]. (Eph 6:10-17; John 6:63) Rather than weapons, there are wonderful things to think on for what comes next; for each and every one of us who rest our hope in Jesus Christ. Lets look forward to our bright future without war, or any need for weapons to kill our fellowman. (JustBibleTruth.com/WhatIsOurFuture.html)

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