QUESTION ON MILITARY AMMO (IN)ACCURACY

[230RN]

In another thread on "Why so much hostility towards 'tactical'," strambo remarked,

...well my M4 only does about 2 MOA with 4X ACOG and non-match ammo at 100yds and I'm a darn good shot.

This brings up a question which I've wanted to ask for about a year. About five years ago I shot up a 20-rd box of 5.56 NATO ammo made in Malaysia in the 60s which was pretty inaccurate in my .223 varmint rifle. Now maybe I was shooting badly that day, or whatever, but that's not the real question.

I kept a single round of it just as a curio, and about a year ago I decided to pull the bullet just for grins.

I examined the bullet and found a small off-center ding in the lead at the base. This ding looked like it was very precisely and deliberately made when the bullet was formed --perfectly circular, about .015" in diameter and about .030 off-center, a little more than midway between the center and the part where the lead meets the jacket at the boattail. It looked like it was about .010 deep by my calibrated eyeballs, and was highly polished, as if it were die-stamped in.

Unfortunately, I have only this one bullet as a sample, and no more military ammo around, either US or other source, to examine.

OK. So somewhere (Hatcher?) I read that ammunition is much more sensitive to irregularities at the base than it is with deformed noses, and somewhere else I read that for full-auto arms (such as the military 5.56 mm weapons) it was better to have the shots disperse than to have ammo that was too accurate.

After all, a number of highly-accurate rounds through one hole in burst fire is not as effective as having the rounds establish a "cone of fire."

So here's the question:

Is some military ammo deliberately made to be slightly inaccurate for the above reason by "dinging" the bases of the bullets --in other words, to establish a "dispersal" of the rounds in battle? (Note that even though any deliberately-made "dings" may be precisely formed, their orientation for each round would be indeterminate, thereby making one round go slightly off to one side, and the next round off in another direction.)

Sorry if this sounds ignorant, but that little ding sure as heck looked like it was put there on purpose, and strambo's remark about his 2 inch groups with non-match ammo brought this question to mind again.

 

[AK103K]

Most military ammo has a 3 MOA acceptance spec. Even if it doesnt meet this spec, doesnt mean it still wont be accepted for another use. 2 MOA seems about right for the 5.56. I have a Armalite M15A4(T) that will shoot tight little almost single hole groups with my reloads, and will not do better than 2" with a lot of military LC69 I have. I also have some of that Malaysian stuff, MAL 2-83 that shoots about the same as the LC.(I'll pull a couple bullets from mine and see what they look like.)

Your right about the bullets base. This is why you see match ammo with a jacketed base and a hollow point. The base is more critical to accuracy than the tip. I have bought "surplussed" bulk FMJ 147 grain .30 for practice, and a friend of mine bought some of the same in 5.56. Surplus is often a term meaning rejected. Just because it says surplus, does not mean its an overrun of good stuff. Some of these people selling this bulk stuff bought lots of rejected stuff at auction, and are selling it as surplus. The bases on bullets we got of both calibers were smeared lead across the base, not the normal nice rolled crimp you usually see. I could not get groups better than 10-12" at 100 yards with the .30's, and my buddy, who was using a .223 varmint rifle that was known for tack driving, was hitting targets two over from where he was aiming.

 

[230RN]

"I have a Armalite M15A4(T) that will shoot tight little almost single hole groups with my reloads, and will not do better than 2" with a lot of military LC69 I have."

OK, but is the inaccuray deliberate? And would they die-punch a ding in the base for that reason (--or maybe by "smearing" the bases, as you note)?

I'm thinking that a precise deformation of the bases, as with a die-punched "ding," would sort of generate a "calibrated" inaccuracy, if you will.

I'd be really interested in what your bullet bases look like when you pull them. I'm also thinking that if they dinged, like every other one, at least one shot in a burst would be to point of aim, and the others would randomize and establish that cone of fire I talked about.

 

[AK103K]

Well, I just pulled one of each. The LC base is nice and clean with the dimple and the MAL is starting to look like the .30 reject stuff I had.

Using that M15A4(T), I dont get much difference in them at 100 yards, although I would guess just looking at the two, the LC would do much better, so I dont know what to say. I do know that when I use Nosler BT's or Sierra match rounds, the results are like night and day. Then again, the brass is also prepped and there is more care in assembling the round.

I have pulled Wolf and Barnaul 7.62x39 and compared their bullets. Wolf has always been kind of hit or miss accuracy wise for me. The Barnaul(SP) has always been better and more consistent. The Wolf bullets are more of the FMJ type rolled crimped base, both the HP and the FMJ, sometimes they are clean, and sometimes they look smeared. The Barnaul SP's have always had a clean jacketed base, much like the Sierra SP Spitzer's. They have also been the most accurate. Of course, just to screw with me, I shot some of the 154 grain Wolf SP's about a week ago and was getting 3-6" groups at 200 yards with them.

 

[NailGun]

2" groups for a mass produced firearm using mass produced ammunition is outstanding! As we are aware, ALL rifles vary just a tad in their chambers. Each GUN will shoot standard ammo better or worse than the one next to it. If ammo could be developed for EACH GUN, even using standard issue components, accuracy would improve. Developing ammo for EACH GUN in the military is NOT feasible. Military ammo needs to be produced by the gazillions.

I reload. I have rifles that refuse to shoot factory rounds under, say, 5" at 100 yds. My developed "pet" loads for those rifles often group just under 1" at 100 yds. Some of the cases I reload have slight imperfections. They still work fine and deliver the accuracy I demand.

The more I reload, the more respect I have for the commercial manufacturers. They have to develop rounds that will perform well in most rifles, under all weather and temperature conditions. If they couldn't accomplish this task, they would go out of business.

As for "die punching a ding", this would be one more step in the manufacturing process, it would take more time, more money, more machinery, and there would be no added benefit.

I do not see a large benefit to having a super accurate battle rifle for the following reasons:

1. More accurate means tighter tolerances. Tighter tolerances means more possibility of jams. M-16's are tight, I have never had one that didn't jam. SKS's are sloppy, I have not got mine to jam yet.

2. The intended target is large enough that 2 MOA is good enough.

3. As the barrel of the rifle heats up, after multiple shots, the groups open up to patterns. Just shoot up a few 30 round magazines with tracers every 5th. and you will see what I am talking about.

4. With open sights, at 300m. your probability of a hit is drops off fast, even with sub MOA ammo. Optical sights will improve this condition.

5. If a one shot stop is necessary, I'm betting the unit has a designated sharpshooter with an appropriate weapon, with the appropriate ammo, to get the job done. For everything else, there is "Ma Duce". NailGun

 

[James T Thomas]

inherent dispersion

I cannot answer your question as to whether the military is deliberately deforming bullets to effect a dispersion.

However, having fired the "old" M16's, their variants, the M60, and the M2, the "cone of fire" effect does not require imperfect bullets. Those weapons buck and shake around so that a good gunner has to hold on and place all his body weight behind them. He still will achieve a "zone" of dispersion that at far ranges where the bullet trajectory has begun a downward slope; the sharper curve of the parabola they follow, which was an elongated "football" pattern as they impacted. Called "plunging fire," and intended for formations of soldiers.
Even a close jungle distances, on automatic fire, the lighter recoiling weapons would disperse. Despite being gripped tight.

My guess, from and engineering viewpoint, would be that the automated machinery producing those bullets had worn out of tolerance and needed adjusted or replacement. Quality control.

Are you aware of our enemy's gun the AK-47 and how it "disperses?"
Now, add to that "unbalanced" bullets, and close range would be the only mode of shooting that would be effective.

A side note to that. In the jungles of S.Vietnam, the untrained V.C. guerillas had very few rounds to train with. When they did receive the AK-47's.
They were trained to wait until the first American of the formation, the "point man" would approach to a distance where you could see the "whites of their eyes," and to shoot for the head. They were renoun for the camouflage they used. It made them blend into the vegetaion very well. The point man assignment was a very risky one because the first round fired in a battle often meant that point man was head shot and gone. They didn't have to be concerned about inaccuracy.

I would doubt if our ordinance department would deliberately specify such bullets. But then, stranger things have happened "in the Army."

 

[Kharn]

Its a production standard/test that the government can apply to assure quality while also recieving competitive bids.

If they said every test sample had to shoot to less than 1moa, no one would bid the contract as you cant insure the chosen test rifle would like that particular powder/primer/case combination.

Kharn

 

[XDKingslayer]

I was under the impression that shooting 5.56 in a .223 was bad. Not saying military ammo is accurate or inaccurate, but if it's not recommended to shoot 5.56 in a .233 could that have been the reason for your inaccuracy?

 

[strambo]

It's not deliberate, but an effort to make the ammo more consistent like match grade ammo would be very costly and not necessary. I was only able to get 2" groups because a) I had a 4X scope and b) they were only 3 round groups. I figured that was about as good as that weapon/ammo combo could do, maybe better than average. I was zeroing off of a sandbagged rest.

2" groups means the weapon/ammo can do 16" or "minute of torso" at 800yds if the shooter can exploit that...so that's plenty accurate. The M4 weapon system can't hang that far out because the trajectory and wind deflection would be horrible. An M16 A4 (flattop) with a scope has made hits to that far in combat I believe, might have been with the 77gr bullet though. Mk262 mod 0, I think it's called.

I read an article in a gun rag about a custom made M4 type Ar15. It shot 1-1 1/2 " groups with good quality civilian ammo and like 2 1/2 - 3" groups with the LC M882 ball. Sounds about right...just not held to the same tolerances, but plenty good for it's purpose. Our LC ammo is a lot better than much of the foreign stuff. Today I was shooting the German's machine gun and one round was jammed back in the case about a 1/2". They told me not to worry about it and shoot it! So...I knew the pressure would be higher...but it was one stout machine gun too. I shot it and couldn't tell. Couldn't hit crap with that MG though (my fault, not the guns)...I miss the M60.

 

[AK103K]

I have a copy of the load data manual for the "Lake City Army Ammunition Plant" dated 1969. In it it lists the specs for each caliber and round loaded there. Just to save time, I'll give you some examples of what they required for some rounds. I can scan the pages later if you'd like to see them whole. It will give you an idea of what the government was looking for in accuracy standards for the different rounds.

5..56mm Ball, M193 -- accuracy...... 2.0" mean radius max. at 200 yards


5.56mm Tracer, M196 accuracy.....5.0" mean radius max. at 200 yards

Caliber .30 (30-06) Ball, M2 accuracy....7.5" mean radius max. ave. at 600 yards

( sort of a interesting note here.... the Caliber .30 has a lot more different types of ammo loaded, including rounds for "overhead fire applications" and frangible rounds used for training. They seem to have stopped it once they moved into the 7.62x51, or at least they did at LC. )

7.62mm NATO Ball, M59 accuracy....5.0" mean radius at 600 yards

7.62mm NATO AP, M61 accuracy....7.5" mean radius at 600 yards

7.62mm Nato Tracer, M62 accuracy....15" mean radius at 600 yards

.50 Ball, M2 accuracy.....9" mean radius at 600 yards

.50 Tracer, M1 accuracy.... 20" mean radius, max. ave, at 600 yards

Caliber .45 Ball, M1911 accuracy....7.46" diagonal(max ave) at 50 yards.

Caliber .45 Ball, M1911, "steel case" (seems they were still loading steel cased .45 in 1969.) accuracy...7.46" diagonal(max ave) at 50 yards.

Caliber .45, Ball, M1911, Match accuracy....3" diagonal(max ave) at 50 yards.


I think one thing that needs to be kept in mind here when it comes to surplussed ammo. Even if it was accepted when new and then released due to age, or other reasons, it may not necessarily meet the specs now. Improper storage, and even different types of ammo for different uses, may offer different accuracy than you are expecting. I've had great lots of older surplus, notably Spanish Santa Barbara 7.62x51, which I would consider match grade, and then I've had Brazilian CBC 7.62x51, which is OK, but very hot. Some lots were actually recalled by the distributors due to rifles failing while using it. I've had other lots of various types that were just terrible, or turned out to be very corrosive, when the were advertised as not, so you never really know just what you are getting until you shoot it. If you find a lot that works well in your rifle, buy up as much of it as you can, as its usually a good deal.

 

[230RN]

THANKS, ALL!

OK, I appreciate all the responses.

Great photos/scans, and great accuracy tables, AK103K! The dimple in the smaller round looks rather like the one that occasioned the question, except "mine" was off-center. So I guess it's just something they do when swaging the jacket down or something. Much ado, I reckon. When I first saw it in bad light, I thought it was an extrusion pip from the swaging, but I then realized it was a hole, not a pip. Another mystery of life.

kingslayer said:

"I was under the impression that shooting 5.56 in a .223 was bad. Not saying military ammo is accurate or inaccurate, but if it's not recommended to shoot 5.56 in a .233 could that have been the reason for your inaccuracy?"

Yeah, I guess that's true nowadays. I know that lately there have been some dimensional differences, and today's 5.56 has much heavier bullets than what used to be the case (55 gr), and this rifle, with its 1 - 14" twist, will not handle bullets heavier than 55 gr --I didn't have to try it, I knew it in advance.

So I will not practice with any military ammo in this rifle at all anymore --no point to just making noise.

That rifle would group 3/4" to an inch with the old 55-grain military rounds. With my handloads (52 gr SX bullets, and about 24 gr 3031 --I 've forgotten the exact powder charge right now) it'll group 3/8" HTG* groups all day long, hot, cold, dirty, clean, whether or not I've had too much coffee. It's no benchrester, but not bad for a sporter-weight.

Soooo, thanks. I just figured maybe they could somehow "regulate" inaccuracy to establish that cone of fire precisely.

------------
* A little humor:

"HTG" groups are what I call those obtained in the long term, with regularity, from year to year. I'm not talking your three-shot target that you take home. I'm talking morning till night, day-to-day, month to month, etc to etc.

My use of the term term "HTG" comes from the days when they were developing the atomic bomb in the Manhattan Project. They needed a code word for plutonimum, so they called it "calcium" in all the documents and correspondence.

Well, by and by, the scientists found that real metallic calcium had to be used for something in their top-secret research. They were in a bit of a quandary as to what to call the real calcium... they couldn't use the term "real calcium," since that would give away the fact that "calcium" actually was a code word for something else --that is, plutonium.

So they settled on the term "HTG calcium" for the real calcium.

The "HTG" stood for "Honest-To-God" calcium.

 

[pack_rat]

The Dimple...

I wasn't quite sure until I saw the photos, but could the dimple be a result of sizing the bullets?
If they were run through a super version of the Lee Sizing Die, nose to tail, the tip of the following bullet would make the dimple. Look at the pic again. Is the dimple not about the size of a bullet tip?

hmm...
===
p_r

 

[230RN]

Aha! Now, pack_rat, that is a darned good guess! Elegantly explains a lot!

Thank you!

 

[strambo]

A "cone of fire" is only desireable in machine guns...and artillery. The recoil of even a very stable machine gun on a tripod will still cause dispertion, more so than engineering less accurate ammo unless taken to an extreme. Feed an M240B M118LR (175gr match) and you'll get the same dispertion anyway because of the recoil.

The US doctrine for rifleman is "one shot, one kill" or as close to that ideal as possible. If we could have our M4's shoot MOA and be reliable and affordable (as in, no cost increase) I'm sure we'd do it. This can't be accomplished though. Machine guns are for fire suppression and fire superiority, rifles (carbines) are for hitting what your aiming at. Even machine gunners are shooting controlled burst and trying to hit targets.

 

[230RN]

strambo and pack_rat:

Many thanks for your information. This was an interesting example of how ignorance of a few facts can lead to a puzzle. I have little practical knowledge of (a) ammo manufacturing processes and (b) auto-fire tactics, so the answer could not have just jumped out at me.

I'm used to handling bullets in reloading one-at-a-time, picking them up from the box and aligning them with my fingers before putting them in the mouths of the cases. The obvious had to be pointed out to me: that in production, at some point the bullets had to be properly lined up for mechanical insertion.

And I had no clear idea of what a cone of fire was --it just sounded like it was "needed" in full auto fire --therefore it could be built-in to the bullets, and the ding looked that it might have something to do with that. (I've never fired anything full-auto, having done nothing but fire single precision aimed shots all my life -- well, "aimed," anyway.)

And if you recall, I pleaded ignorance in my original post.

Sooooo, many thanks !

Me go now.

 

[Manedwolf]

The US doctrine for rifleman is "one shot, one kill" or as close to that ideal as possible.

Does that apply only to snipers and such? I thought the very idea of 20th century military small arms wasn't necessarily to kill outright, but to wound enough to stop as a threat and cause the enemy to expend their resources and slow their movements to deal with their wounded?

Not that that works in current asymmetrical warfare against suicidal sorts, but I believe that used to be the idea.

 

[strambo]

Manedwolf, at a strategic level that may have been the case at one time. After Vietnam, at the user and training level, accuracy began to be emphasized. M16s no longer even have a full auto option, just 3 round burst. 3 round burst isn't used very often.

A better statement would be "one shot, one hit" I guess, but that is an ideal that non-snipers will never achieve. The point is, that is the goal for our rifle armed soldiers. Light and General purpose MGs, grenade launchers, artillery and air support are all used to suppress, and achieve fire superiority (as well as hopefully kill a lot of 'em). Hits from those weapon systems are always welcome too though.

If you had a squad with no machine guns for whatever reason, you would designate 1 person per fire team to be in that role. Give them lots of ammo and tell him to engage on burst to suppress while the riflemen return precision fire. There are tactical situations where you might all fire at a high rate, such as in the first few seconds of an ambush (yours), reacting to a close ambush (the bad guys) or breaking contact.

 

[44AMP]

Ammo Accuracy

There is inaccuracy built in to certain ammunition. This is intentional, at leat in some calibers. The .50cal BMG has a "built in" inaccuracy with ball ammo. This is done by a large (comparatively) allowed variation in the bullet weight.

This is done to aid dispersion, to produce that "cone of fire" that machineguns are supposed to. Old Ma Duece tries hard to put all her shots in one hole, like a good rifle. It doesn't happen of course, but the dispersion was not as much as with other designs (at the time of origination), so some was built in to the ammo, to make up for the "shortcommings" (accuracy) of the M2.

Don't take this to mean the M2 is a benchrest gun, just that it is generally more accurate than most other machineguns.

I can't say for certain about other service calibers right now, but I have the +/- specs on most of them somewhere. When I run across them, I'll check.

There is military ammo (ball, tracer, AP, etc.), match ammo, and sporting ammo. It doesn't take a whole lot of thought to figure out that the tightest specs are going to be on match and sporting ammo. Match ammo, because you want to win, and accurate ammo is a basic first step. Sporting ammo, because hunters want to hit, and if your ammo isn't accurate enough, they will buy somebody else's.

Then there is the whole thing about the rifles. Back in the 1970s, the standard for overseas shipment of an M16A1 was something like 8 MOA. Less than that, it could go overseas (combat, etc) more than that it stayed in the States (training, etc). I wonder what the standards are today?

 

[GungHo]

Is some military ammo deliberately made to be slightly inaccurate for the above reason by "dinging" the bases of the bullets --in other words, to establish a "dispersal" of the rounds in battle? (Note that even though any deliberately-made "dings" may be precisely formed, their orientation for each round would be indeterminate, thereby making one round go slightly off to one side, and the next round off in another direction.)

Sorry if this sounds ignorant, but that little ding sure as heck looked like it was put there on purpose, and strambo's remark about his 2 inch groups with non-match ammo brought this question to mind again.

2 MOA isn't going to create a dramatic dispersal pattern. I mean, think about it... it's just a 2" circle at 100 yds. If it's round with a maximum effective range of 600 yds that's not going to do much for you unless you're going up against the Kate Moss Army.

The reason military ammo isn't as accurate as match loads or handloads is because it's cheap.

 

[U.S.SFC_RET]

James T Thomas Quoted

However, having fired the "old" M16's, their variants, the M60, and the M2, the "cone of fire" effect does not require imperfect bullets. Those weapons buck and shake around so that a good gunner has to hold on and place all his body weight behind them. He still will achieve a "zone" of dispersion that at far ranges where the bullet trajectory has begun a downward slope; the sharper curve of the parabola they follow, which was an elongated "football" pattern

The cone of fire that you are talking about is laid down at long distances with a machine gun such as the M2 .50 cal, the correct way to lay a cone of fire is to use a tripod and a T&E device. A T&E Device is traversing and elevating mechanism that will hold the gun in a fixed position to permit an effective cone of fire. Cones of fire are especially deadly in dead zones. Dead zones are areas that normally cannot be accessed like ditches and ravines by small arms fire at short range.

You get what you pay for when you buy Military surplus ammunition. Good ammunition isn't just ammunition. If you just want to shoot tons of milsurp ahead it is a free country. If you want to wear out barrels, again it is a free country. Practice doesn't make perfect, perfect practice makes perfect.

 

[Grump]

Please note that the "mean radius" statistic *generally* equals a group sizes extreme spread of about 3 times the radius. Some of the best .30-06 M72 Match ammo ever made tested mean radius of just under 2.0 inches at 600 yards, or a 6-inch group....out of machine-rested test barrels. 7.62mm M118 (the old 173-gr FMJBT open-base stuff) generally did marginally but consistently better than M72.

That 5-inch mean radius tracer stuff can be relied on to shoot them all inside a 15-inch circle at the 200-meter distance specified, a bit less than 7 true MOA (@1.1 inches at 100 yards = @ 1.19 inches at 200 meters).