Makeup of NATO spec 7.62x51mm rounds?

[ADB]

I was sorting my Boxer-primed 7.62x51mm rounds the other day, and I decided to test them with a magnet. Something interesting I noticed--all the Lake City mil-spec rounds that I had attracted the magnet, presumably due to a layer of steel between the copper outer layer and the lead core.

But the other NATO-spec rounds I had, including NATO cross stamped stuff manufactured in Israel and elsewhere, did not attract the magnet, which I assume means that they're pure copper/lead.

Can anyone explain why there would be this variance in NATO-spec rounds? It would seem to me that either having a layer of steel or not having it would noticeably affect the performance of the round (penetration, etc.), making it hard for allied forces to share ammunition supplies.

[azredhawk44]

It's a very mild soft steel.

You'll find the same variation with other 7.62NATO producers as well.

Be thankful that it has an appropriate amount of powder and a bullet between 140 and 160 grains in weight and call it good. You should see some of the stuff that Jignash produces on the Indian assembly line. Copper jackets with no lead core, mixed powder types in the same case, variations in powder charge from 15 grains to 45 grains... Indian ammo is the definition of "sucky ammo."

Allies can share steel core and non-steel core ball ammunition of approximately 150gr weight, and still have a common POI within 4MOA of each ammunition manufacturer.

[Jimro]

Can anyone explain why there would be this variance in NATO-spec rounds? It would seem to me that either having a layer of steel or not having it would noticeably affect the performance of the round (penetration, etc.), making it hard for allied forces to share ammunition supplies.

The spec portion is dimensions and pressure. Everything else is really up to the country of origin. Britain is fond of 144 gr bullets, the US uses 147 gr bullets. Even pressure is up for grabs as British SS109 is often lower pressure than Lake City M855.

Jimro

[HorseSoldier]

What he said. There's wiggle room in the NATO specs that allow for some variation in recipes.

[ADB]

I figured there would be manufacturing differences, but I'm just surprised there's such a difference in the bullet composition. Correct me if I'm wrong, but won't even a soft/mild steel casing between the copper and the lead keep the bullet together longer, allowing for better penetration through things like stone or wood?

[jman841]

Not really enough to notice. as soon as the bullet makes contact the soft steel and copper deforms. Now if it had a steel penetrator like the green tip 5.56 we use, that would increase penetration.

[DMK]

Can anyone explain why there would be this variance in NATO-spec rounds?

The spec portion is dimensions and pressure. Everything else is really up to the country of origin.

I may be wrong, but it seems to me that NATO specs are only to insure that the ammo will work reliably in all the NATO member's rifles so that they could share supplies in event of a war.

I don't think that actual ballistics, especially terminal ballistics were considered.

Think about the politics involved here. It's hard enough to get your own country to adopt a new round. Imagine trying to get everyone in NATO do design a bullet to one exact specification right down to bullet construction?

[BlueTrain]

To call it politics is misleading. The militaries of different countries have their own interests and do not necessarily care that much about what other armies think about the situation. All of this happens at a defence department level, not in legislative bodies. It involves a lot of engineers flying all over the world trying to get everyone's minds working the same way, not an easy task. My late father-in-law, an aero-space engineer (formerly aeronautical), spent many years doing just that. And as you know, engineers always want you to see things their way and no other. And all problems have engineering solutions.

There is a surprising amount of sharing of resources in a war zone, although standardization isn't everything. The differences in "standard" items aren't enough to worry about but there are differences, to be sure.

[Jimro]

I may be wrong, but it seems to me that NATO specs are only to insure that the ammo will work reliably in all the NATO member's rifles so that they could share supplies in event of a war.

I don't think that actual ballistics, especially terminal ballistics were considered.

Each country works the terminal ballistics point on their own, for example some European countries use a thicker copper jacket on their SS109 ammunition to prevent fragmentation as to not cause "unnecessary suffering" by the Hague convention...

But you hit the nail on the head, it's about being able to put any round in any rifle and have it go "BANG" in the direction of the Communist horde...

Jimro

[DMK]

To call it politics is misleading. The militaries of different countries have their own interests and do not necessarily care that much about what other armies think about the situation. All of this happens at a defence department level, not in legislative bodies.

I may have mislead. I didn't mean at the whim of politicians. I meant the politics within and between the various military and defense industries. Although I'm sure SecDef level politicians get their say too (McNamara sure did).

[BlueTrain]

Well, I did say it happened at the defence department level. It certainly doesn't happen at ground level. But I wonder how the whole thing works out in practice? I mean, who decides to lend or give the allies truckloads of ammo? Theater commander (if there are such things anymore) or lower down.

The other side also has largely standardized a lot of their equipment over the years, almost entirely Soviet in origin. Yet even theirs has a lot of variation. Not everyone ended up using the AK rifle, even though nearly everyone did, including Finland. Likewise, although the .30 Tokarev was the standard early in the post war period, the Czechs produced a version that was possibly too hot for actual Tokarev pistols even though the .30 Tokarev itself is a pretty intense round. But I've never read anyone's work on comparing Eastern Bloc ammuntion produced in different countries.

[DMK]

But I've never read anyone's work on comparing Eastern Bloc ammuntion produced in different countries.

Here's one comparison.

http://www.7.62x54r.net/MosinID/MosinAmmo.htm

Having a considerable amount of 7.62x54R and 7.62x51 surplus ammo in my collection, I've wasted (or enjoyed) much range time comparing the ammo of different countries in the same rifles. I'd say that the Warsaw Pact ammo is standardized just as much as the NATO ammo, at least in these two calibers (although the Warsaw Pact made a major change in bullet weight mid-coldwar, it was across all countries). I've found a battle zero on a rifle will hold pretty much true no matter what country's ammo you shoot (assuming the same bullet weight in '54R).

The other side also has largely standardized a lot of their equipment over the years, almost entirely Soviet in origin. Yet even theirs has a lot of variation. Not everyone ended up using the AK rifle, even though nearly everyone did, including Finland.

A good example of that was the Czechs with their CZ-52 carbine. A ground up design similar to the SKS, and originally chambered in a proprietary 7.62x45, they finally chambered it in 7.62x39 to maintain compatibility with other Warsaw Pact nations.

As far as the AK, Russian gave the other countries the designs, the machinery and even sent over engineers to start production. Even then, many countries changed the design, some fairly radically to accommodate their own needs.

The Czechs, again decided to just build their own assault rifle from the ground up more like the NATO way of doing things.

[BlueTrain]

Excellent reference, thank you. It hasn't been all that long since just about the only 7.62Rx53 (or 54, as I've also seen it) was Norma, one of the more expensive brands of ammuntion. But it was commercial and available in hunting loads.