Why steel in surplus ammo?

[BenningBoy]

What would have been the reasoning for the steel content (either jackets or core) in Soviet bloc surplus ammo? I have a variety of 7.62x54R, some dated 1947, and can't understand why they would manufacture it that way. Wouldn't have been a pain to put these components together in 1947? Does a mild steel core have some benefit? Lead shortage? Just curious about the history.

[Jackal]

It was a cost saving measure. Steel would penetrate better than lead, but still, I wouldn't call it armor piercing (unless it is actually armor piercing by design).

[daschnoz]

Steel is cheaper than lead or copper and is more easy to come by.

The steel in comm block steel core ammo is no harder than coat hanger steel. It has no more armor piercing ability than lead. Of course, the BATF doesn't see it that way, but ass hats will be ass hats.

I don't think steel core is quite as accurate as lead core, but in war (which this ammo was designed for), minute of center mass is close enough.

[Karl/PA]

There's also another factor. By international treaty, all military small arms ammunition had to be designed not to expand upon impact and cause additional unneeded injury to an already wounded soldier. This seems to have gone by the wayside mostly, though some things are still banned, gas, napalm, etc.

If you ever read Ho Che Minh's and Mao Tse Tung's WW2 writings, both agreed that it was better to wound any enemy on the battlefield than to kill him. Killing a soldier only takes one man out of combat. Wounding one takes several out, to care for the wounded one.

[BenningBoy]

I was thinking along those lines, but assumed lead was cheaper than steel. Wouldn't steel jackets play hell on the bores of the time?

[Agent Ronin]

I was thinking along those lines, but assumed lead was cheaper than steel. Wouldn't steel jackets play hell on the bores of the time?

It has been shown that the wear on the bore from shooting bi-metal ammo is negligible. The steel used in the jacket is a very, VERY soft steel.

FYI, US Cal. 30 ammo used GMCS jackets which contained steel in the copper alloy and was made that way from 1906 to 1970's.

[cosmo05]

I was thinking along those lines, but assumed lead was cheaper than steel. Wouldn't steel jackets play hell on the bores of the time?

The hot gases are what does a throat or barrel in. The steel is soft, like copper and does absolutely no additional harm to the barrel.

[BenningBoy]

This is all historically fascinating to me. While alot of their stuff seems beautifully simple in design (AK-47), other stuff is way over-engineered (cylinder on Nagant pistol). I thought maybe this extended to their ammo, as well. Thanks guys.

[PA Rifleman]

This is all historically fascinating to me. While alot of their stuff seems beautifully simple in design (AK-47), other stuff is way over-engineered (cylinder on Nagant pistol). I thought maybe this extended to their ammo, as well. Thanks guys.

The previous posters are essentially correct. Initially it was a material saving measure during W.W.II and became a manufacturing standard.

Cases:
Cases are made from a specific type of brass called "cartridge brass" (30% zinc) which is ideally suited for the conditions present during firing. Another benefit to brass is the dissimilar metals between the brass and the steel in the chamber help unseal and separate the case immediately after chamber pressure falls following discharge. Using a steel case causes sticking, welding and high opening force, which increases extractor wear and stuck cases.

During W.W.II copper and cartridge brass in particular became strategic materials, and most participant nations sought ways to conserve it. Germany, the USSR & the US all made steel case ammunition. As far as I know, only the USSR, Warsaw Pact nations & China continued with steel case ammunition after W.W.II. It works as well as brass cased ammunition, but requires an interface coating to prevent seizing during firing. The Germans painted theirs with lacquer paint, the Russians continued this. Later, they developed a surface flash coating of copper or brass that gave similar anti-seizing properties as copper based casings but retaining steel as the base casing material. I believe the Russians call this material Tombac and also use it for bullet jackets. Steel cases require a lot more force to resize down during reloading, but most of these nations don't bother reloading so that isn't an issue.

All other factors equal, steel cased ammunition generates higher chamber pressure due to greater case neck bullet retention, and also results in higher extraction force after firing. For firearms designed for this, it's normal operation. SKS rifles and Kalashnikovs are specifically designed to work with this type of ammunition. Steel case ammunition in a firearm not designed to use steel case ammunition may experience early extractor wear or failure with prolonged use.

Projectiles:
Soft steel core ammunition has some advantages over lead core. First, lead is more expensive than cheap steel. Also, the lead cores are swaged, a process similar to your Play-Dough machine pooping out interesting shapes and colors. Voids, or air pockets are the bane of bullet makers on both sides of the world. Voids cause imbalance, ruining any chance of accuracy. Swaging greatly reduces the occurrence of voids, but only steel cores eliminate it. Another side-effect of steel core bullets is enhanced penetration compared to lead, but nowhere near the performance of a true armor-piercing bullet*. The big selling point of steel core rifle bullets is the Gaspolster Effect (more), which is essentially a self-sealing low friction bullet design. Steel core bullets apparently can be designed to expand slightly to match the rifling profile in a barrel, rather than the traditional method of force-swaging a bullet down to the rifling land size. It appears the jacket displaces outward under gas pressure and forms a pressure-assist seal, and the steel core drifts forward preventing the bullet tip from being blown off during peak chamber pressure. It's a modernized version of the old Minie bullets of the Civil War muskets. The AK-74 uses this design, and I recall they use a Tombac jacket to pull it off.

*Armor-piercing bullets have an ultra-hard tungsten core, with is machined to the final size. This bullet is designed to penetrate at the expense of no noticeable expansion. Armor-piercing bullets are simple kinetic energy weapons, so they require a lot of speed to work correctly. Most AP rounds are typically W.W.II leftover 30-06 rounds. It's obviously an anti-material round.

[BenningBoy]

Thank you, Pa Rifleman. Last question. Since all were concerned with stretching materials as far as possible, why did they choose the priming system that they went with? Didn't this make the ammo too difficult to effectively reload?