7.9 S.m.K. penetration


Standard data for SmK is a 11 mm and 12 mm [verbessert] from 100 m / angle 90.
I wonder if the standard 7.9 mm SmK bullet will penetrate a 15mm thick armor plate from 100 m / angle 90 ?
Or 11 mm is the limit only in tests - based on technical condition? In acceptable tests of PL made this type bullet - was required a 20 x piercing from 25 selected bullets / 80%.

ps. standard core for SmK in 30’s - 40’s is made from tungsten steel, or other types of steel?


The specification for acceptance (TL 13/1001 of 1932) prescribed that out of 20 shots at least 18 had to penetrate a 11 mm “Panzerblech”.
The prescribed core steel had approximately:
1.2 % C, 1.2 % W, 0.15 V, 0.2 % Cr, 0.3 % Mn and 0.25 % Si according to the same specification.
As in the U.S. (.30 AP M2) the tungsten became too scarce and had to be dropped in wartime.

I’m trying to compare different types of cores / piercings.

Experimental bullets with a exposed cores, Vo ~ 820 m/s, [so Vo ~the same for SmK and PL made wz.“P” - Mauser type], have a better penetrate - 15 mm from 100 m 90 angle. Weight of cores ~5 g max., based on dimensions - its a “light” steel core, not WC [!].
If this is not an mistake, what could improve the penetration of almost 50% in 7,9 x 57 Mauser ~Vo=820 m/s? [similar armored plates were probably used, maybe standard in late 30’s].

Penetration is an extremely complex matter. Conditions, for example how the armour plate is mounted, have a big influence on the result. Not to mention steel quality. In Germany, yield strength was used to describe steel quality. Others used hardness (Brinell, Rockwell C, Vickers, you name it). All other things equal, it has been proven that a longer penetrator is better.
I personally have come to the view that results from tests made at different times by different institutions are not really comparable.

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A couple of years ago a deer friend invited me to test the SmK versus SmK-H.

He did not want to shoot with an MG on the target, a one inch steel plate, only with a rifle.
It was a little dangerous because the SmK cores could come back after they hit the plate.
He was right. During the shooting some cores whispered over our heads.

Well, a picture tells more than a lot of writing.

The shooting range in Arizona.

The SmK on the target.

On the right with five SmK-H.

On the back of the plate, only the SmK-H came true.

The plate. Picture from the back.

I was very impressed.



Nice, thanks! What was the shooting distance?

I am not sure. Could be over 100 meters.
The smoke is from the inpact of a B-Patrone.


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