Better than M4, but you can’t have it

[Dominique R. Poirier]

“Two thoughts: 1) In the 7.62 v. 5.56 debate a round in the 6.5 - 6.8 range would have been a good common sense compromise; 2) It still probably isn't worth changing, and that includes the rifle as well as the round. Just keep what we have unless something revolutionary can be fielded.”

The main reasons justifying the evolution toward the 223 ammo were that combat ranges had significantly shortened from WWII on and that a man could carry about 180 rounds of .223 instead of an average of 60 to 90 maxi with bigger ammunitions such as 8mm and .308. The Germans understood that first and invented the first assault rifle (the Sturmgewehr MP 43, and MP 44) firing a shortened version of the 8mm Mauser with a case's length reduced to 33mm instead of the 57mm of the classic 8mm Mauser. This gun and its ammunition seems to have inspired Mikhail Kalashnikov.

Long range shootings are now traditionally left to snipers who are trained to shoot at distances superior to 200-300 yards with .308 ammo and bigger. The classic .223 begins to loose significantly in accuracy beyond 200-250 yards whereas the reasonable limit with .308 is in the surroundings of 600 yards.

“What would be revolutionary? I don't know, but a couple of things come to mind: caseless ammo (….)”

Caseless ammos have been the object of serious experiments in Germany with HK experimental assault rifles during the late 70’s; but some problems, such as spontaneous auto-ignition, were never totally solved. Thus, HK gave up this project.

“(….) as well as railguns and coilguns. I have no idea if any of these can be made reliable and infantry proof in a shoulder fired weapon. The experiments that are going on now with railguns and coilguns seem to be with larger weapons such as naval guns.”

From recollection an electromagnetic pistol has been made in United States during the late 60’s or 70’s I believe but the performances and technical constraints of this experimental gun proved to be unsatisfactorily.

“I don't know why caseless ammo (how about a 6.5 or 6.8 caseless?) hasn't been pursued.”

6.5 and 6.8 rounds get us back to the problem of the number of ammunition a soldier can carry. During WWII Italians and Japanese soldiers used 6.5 ammunition whose cases’ length were superior to 50mm and whose case diameter at the bottom were similar to this of a .308, 8mm Mauser or 30-06 U.S. See the ballistic performances of modern civilian .243 to .270 Winchester for comparison.
Hard to make this diameter’s case smaller as the Soviets experienced it with the 7.62 X 39 Kalashnikov. The finally opted for a 5.56 X 39 circa 1974 (Kalashnikov AKS 74).
Remember also that the WWII .30 M1 ammo (7.62 X 33mm for U.S. M1 and M2 carbines) whose diameter at the case’s bottom is smaller and close to this of a 32 ACP proved to be unsatisfactorily owing to its poor ballistic performances and power.

[J.C.]

The problem is not that 308 is a better round than 223, but that the army uses a small grain steel core bullet. A 223 moving at arond 3000ft per sec with a steel core is designed to pentrate a flak vest and still provide leathality to the target. Further, steel cores where inserted to stop the use of lead. Any good deer hunter or soldier can sit down and tell you why a fast moving bullet with a solid core is bad for bussiness. Personall I hunt with a 257 weatherby mag. IT is 25 caliber bullet on a 7 mag casing. It moves with a 100 Seirra Boat tail at about 3700 FPS. With that kind of speed and a FMJ bullet, little bambi dosen't know its been shot, and even through the vitals can run a hell of along way. However, if you change that to a 117grain Round Nose bullet designed for maximum expansion moving about 3200 FPS, it turns bambis insides to jello. So as a joe carrying my M4, I'm not concerned that I have a 223. I just don't like the grain or type of bullet that we use. If you look at the hydrolics of the AK round agianst the Hydrolics of our standard 5.56mm, you can see the difference of why a small bullet is not problematic.
Its the hydrolic effect that the bullet achevies that is important. Furthmore, when use say that a 308 has better ballistics, thats not what your talking about. What I'm gathering from your conversation is ft pnds of energy delievered of target. Thats only a portion of ballistics. The 308 dose not really have that great of ballistics, their are much better rounds when it comes to that.

[Dominique R. Poirier]

The reason for using lead to manufacture bullets owes to two or three main reasons which constitute an advantage over nearly all other metals:

is at the same time heavy and soft;
it is inexpensive.

I explain why. Lead is a metal soft enough to be easily shaped in a rifled barrel without generating significant and dangerous increase of pressure during the combustion of the powder. A classic rifle’s barrel firing fast and powerful ammunition can undergo pressures as high as 3,500 to 3,800 metric kilo per square centimeter (or bar). For the purpose of comparison, the maximum pressure allowed in a 12 gauge shotgun barrel is about 1,200 bar.

Other metals such as steel or tungsten carbide, for example, are unsuitable for rifled barrels because they are too hard metals to take the shape of a rifled barrel. They would just make the barrel blow up if ever someone attempted to use such a bullet in a rifle. That’s why there is a need to jacket or to circle these metals into or with softer metals such as copper.
In the case of big calibers relevant to the field of artillery (say, above .50) the recourse to copper-circled shell entails a relatively fast wear of the barrel because the shell is in steel and not copper-jacketed (there are many interesting things to say about this point and I’ll be pleased to elaborate on this other fascinating subject if ever someone is interested in artillery from 30mm caliber on).

Actually, the best metal for a rifle bullet should be platinum because it is heavy, harder than lead, and it can bear much higher temperatures than lead. But platinum is too rare and too expensive to be shot.

We are constantly looking for heavy metals to manufacture bullets because there is a need to keep the maximum kinetic energy possible as long as possible. Air density tends to slow a bullet speed; therefore the best remedy to that problem is to make a bullet as heavy as possible for a given diameter. Also, more kinetic energy means better perforating power, of course (let me brush aside the question of stopping power for a while, which would make me wandering from the matter at hand).

Impoverished (or depleted) uranium is still a better metal that lead, owing to its weight; but there are many problems with that metal. Impoverished uranium is uranium remaining after removal of the isotope uranium-235. It is primarily composed of the isotope uranium-238. Since depleted uranium contains less than one third as much uranium-235 as natural uranium, it is weakly radioactive and an external radiation dose from depleted uranium is about 60% of that from the same mass of uranium with a natural isotopic ratio. At standard temperature and pressure it is a very dense metal. Due to its high density the main uses of depleted uranium include counterweights in aircraft, radiation shields in medical radiation therapy machines and containers for the transport of radioactive materials. The military uses depleted uranium for defensive armor plate and its pyrophoricity has made it a valued component in other military applications, particularly in the form of armor-piercing projectiles (anti-tank 30mm shells for General Electric machine guns on Fairchild A-10 airplanes, as best example).
Try to saw a bar of impoverished uranium with a mere metal handsaw and you’ll see an amazing shower of sparks as if you were doing the same with a powerful metal electric saw against ordinary steel… Metal temperature rises considerably during this simple experiment owing to friction and to the atomic weight of this metal.
Depleted uranium behaves in the body as natural uranium does and that’s why it would be unethical to currently use it against humans in small arms.

Now, the problem we have with lead is its very low melting point which is 621.43 °F only. Using full lead bullets in firearms is possible as long as the speed is not in excess of about 1,300 to 1,500 feet per second. These melting point and hardness can be slightly modified by the adding of antimony in it. Beyond 1,500 feet per second a lead bullet melts, buckles, and no longer takes the shape of a rifled barrel. As a result it totally loses in accuracy; even at short distances. That’s why we jacket it with copper, another relatively soft metal whose melting point is much higher.

About “boat tail” shaped bullets.

This shape has been invented first circa 1900 by the French Army, though I am not sure if they were the first to discover it (other and discrepant clues are welcome). Anyways long range rifle shooting competitions commonly existed in France during those earlier times. Shooting distances were of 1,000 meters. Targets were horsemen silhouettes and the rifles and ammunition shooters used was the Lebel rifle model 1886 M-93 in 8mm Lebel. Full metal jacket boat shaped 8mm bullets just did it the best.
Actually, the boat-tail shape has been the best aerodynamic shape offering the best accuracy to a bullet or a shell until then, and that why it is largely used nowadays in small military arms and in artillery as well.

“Personall I hunt with a 257 weatherby mag. IT is 25 caliber bullet on a 7 mag casing. It moves with a 100 Seirra Boat tail at about 3700 FPS.”

Yes, your choice of Sierra bullets is a good pick and the best I know and experimented with that caliber is the Sierra Match 100 which is a FMJ boat-tail shaped bullet (the same as yours, it seems). You may improve the kinetic energy and the stopping power in using round nose shaped bullets, but this will be done at the expense of accuracy at long distances when compared with the former.

Weatherby ammunitions are characterized by their higher speed and power and are very good ammunitions for hunting. Weatherby hunting rifles are heavier and more expensive than other standard rifles because the particular ammunitions they use develop unusually high pressures. This explains why the case of any Weatherby cartridge is reinforced at the bottom. If not, the cases would often break up under pressure.

Now, bear in mind that speed is not synonym of accuracy; quite on the contrary. I will explain why with more details in another comment, if ever you want it, since it would make this one much longer.

“The 308 dose not really have that great of ballistics, their are much better rounds when it comes to that.”

Sorry to disagree a bit, but the .308 is the best compromise one can find nowadays when considering modern military ammunitions for small arms. A similar equivalent in the civilian realm is the .300 Savage which offer a very good accuracy.

[FL-CRACKER]

The problem is not that 308 is a better round than 223, but that the army uses a small grain steel core bullet. A 223 moving at arond 3000ft per sec with a steel core is designed to pentrate a flak vest and still provide leathality to the target. Further, steel cores where inserted to stop the use of lead. Any good deer hunter or soldier can sit down and tell you why a fast moving bullet with a solid core is bad for bussiness. Personall I hunt with a 257 weatherby mag. IT is 25 caliber bullet on a 7 mag casing. It moves with a 100 Seirra Boat tail at about 3700 FPS. With that kind of speed and a FMJ bullet, little bambi dosen't know its been shot, and even through the vitals can run a hell of along way. However, if you change that to a 117grain Round Nose bullet designed for maximum expansion moving about 3200 FPS, it turns bambis insides to jello. So as a joe carrying my M4, I'm not concerned that I have a 223. I just don't like the grain or type of bullet that we use. If you look at the hydrolics of the AK round agianst the Hydrolics of our standard 5.56mm, you can see the difference of why a small bullet is not problematic.
Its the hydrolic effect that the bullet achevies that is important. Furthmore, when use say that a 308 has better ballistics, thats not what your talking about. What I'm gathering from your conversation is ft pnds of energy delievered of target. Thats only a portion of ballistics. The 308 dose not really have that great of ballistics, their are much better rounds when it comes to that.

Great points J.C. I agree completely with you as far as the type of rounds we're using being insufficient. Same goes for the 9x19 (9mm), if we could have better ammo other than FMJ, it would make all the difference in the world, especially when the enemy is all jacked up on meth and what not...

I've always viewed both the 5.56 and 9x19 as surgical tools anyway, that are designed for surgically taking out vital organs in a proficient manner. Knock down power is irrelevant for those tasks in my opinion if you are using the rifle properly and placing your shots properly. The M4 is a solid weapon for our purposes and has vastly improved over the years. Add an M203 grenade launcher to that and you just increased your chances of having superior fire power ten fold.

An example of knock down power being irrelevant that I can think of is a good friend of mine who was a 19D/Cav Scout during the Invasion of Iraq in '03 and deployed again later in '05. Many of those guys had 1911's of some form that they picked up over there, and had magazines shipped to them whether we choose to believe it or not it happened. I've heard of incidents where these guys emptied all 7 rounds into insurgents at less than 5 meters to contact and them still not going down, yet one bullet to the central nervous system using an M9 is sufficient to drop them in their tracks everytime. Shot placement is always one of the most important things in combat.

Most importantly though; it ain't the Arrow, it's the Indian.