Czech out my Steel Moon Bullets (Photo Heavy)

[Miso Beno]

Several months ago 80 rounds of rather evil looking surplus 7.62x39 fell into my lap. I mentioned these cartridges on another forum and came to the conclusion there was a remote chance they could be Nitro proof loads, and that they were Czech in Origin. Not being one to find out if these rounds were dangerously hot or not with my face I decided to sit on them until I could take time to properly dissect one and post the results for others to see.

This past Friday I finally got some time in the shop to sit down and properly document one cartridge of the evil black bullets as well as two reference rounds.

Section 1: Initial Cartridge Appearance and Measurements
http://ruserio.us/images/1/multi_comp.jpg
Top to Bottom: Wolf, AYM (Czech,) Winchester

WOLF
http://ruserio.us/images/1/wolf_oaw.jpghttp://ruserio.us/images/1/wolf_oal_tall.jpg
http://ruserio.us/images/1/wolf_head.jpg
Wolf Cartridge
Overall Weight: 251.3 Grains
Overall Length: 2.184" (inches)
Case Head Markings: "7.62x39 WOLF"
Notes: Steel cased, full copper jacket, Grey polymer/lacquer coating on case.


WINCHESTER
http://ruserio.us/images/1/win_oaw.jpghttp://ruserio.us/images/1/win_oal_tall.jpg
http://ruserio.us/images/1/win_case_head.jpg
Winchester Cartridge
Overall Weight: 275.1 Grains
Overall Length: 2.164" (inches)
Case Head Markings: "7.62x39 WINCHESTER"
Notes: Brass Cased, full copper jacket, no coating

aym
http://ruserio.us/images/1/aym_cartridge.jpg
http://ruserio.us/images/1/aym_oaw.jpghttp://ruserio.us/images/1/aym_oal_tall.jpg
http://ruserio.us/images/1/aym_head.jpg
Wolf Cartridge
Overall Weight: 248.7 Grains
Overall Length: 2.189" (inches)
Case Head Markings: "69 aym"
Notes: Steel cased, full steel jacket, Grey polymer/lacquer coating over entire cartridge.


Section 2: Pulled Component Measurements

WOLF
http://ruserio.us/images/1/wolf_proj.jpghttp://ruserio.us/images/1/wolf_proj_length.jpg
http://ruserio.us/images/1/wolf_proj_width.jpghttp://ruserio.us/images/1/wolf_case_length.jpg
http://ruserio.us/images/1/wolf_proj_core.jpghttp://ruserio.us/images/1/wolf_powder.jpg
http://ruserio.us/images/1/wolf_proj_weight.jpghttp://ruserio.us/images/1/wolf_pow_weight.jpg


Wolf Measurements
-Bullet Notes-
Type: FMJ Boat Tail
Jacket Material: Copper
Core Material: Lead
Length: 1.048"
Width: .310"
Weight: 122.8 Grains
-Case Measurements-
Type: Steel Case, Polymer/Lacquer Coating, Crimped
Length: 1.520"
-Powder Measurements-
Type: Extruded Powder
Weight: 23.7


http://ruserio.us/images/1/win_proj.jpghttp://ruserio.us/images/1/win_proj_length.jpg
http://ruserio.us/images/1/win_proj_width.jpghttp://ruserio.us/images/1/win_proj_core.jpg
http://ruserio.us/images/1/win_case_length.jpghttp://ruserio.us/images/1/win_powder.jpg
http://ruserio.us/images/1/win_proj_weight.jpghttp://ruserio.us/images/1/win_pow_weight.jpg
Winchester Components
-Bullet Measurements-
Type: FMJ Spitzer
Jacket Material: Copper
Core Material: Lead
Length: .846"
Width: .310"
Weight: 121.7 Grains
-Case Measurements-
Type: Brass, Crimped
Length: 1.523"
-Powder Measurements-
Type: Ball Powder
Weight: 22.9


http://ruserio.us/images/1/aym_proj.jpg
http://ruserio.us/images/1/aym_proj_length.jpg
http://ruserio.us/images/1/aym_proj_width.jpg
http://ruserio.us/images/1/aym_proj_core.jpg
http://ruserio.us/images/1/aym_case_length.jpg
http://ruserio.us/images/1/aym_powder.jpg
http://ruserio.us/images/1/aym_proj_weight.jpg
http://ruserio.us/images/1/aym_pow_weight.jpg
"aym" Components
-Bullet Measurements-
Type: FMJ Boat Tail
Jacket Material: Mild Steel
Core Material: Mild Steel
Length: 1.046"
Width: .310"
-Case Measurements-
Type: Steel Case, Polymer/Lacquer Coating, Crimped.
Length: 1.521"
-Powder Notes-
Type: Extruded Powder
Weight: 23.0 Grains

Notes: Notice the presence of rust on both the cartridge jacket and core. There was similar rust inside of the casing itself that I neglected to photograph.


I only performed a cutaway on the "aym" bullet due to time constraints but you'll notice that the projectile is a two piece cartridge that consists of a mild steel jacket and a mild steel core. The hardness of the two components was the same, and the shavings of both components were magnetic. Surrounding the core is a medium of a softer silver colored metal that I believe is a tin or lead brazing compound because of its relative softness compared to the core and the jacket.

http://ruserio.us/images/1/aym_proj_cutaway.jpg

At this point I'm at a loss as to what the purpose of the bullet is. The powder type and weight leads me to believe that this is a standard pressure load but the steel jacketed projectile confuses me. While I was making the cutaway I was expecting to hit a hardened tungsten core which would have indicated the bullet was armor piercing but the core proved to be just as mild as the jacket which would limit the round's ability to penetrate hardened steel armor. Ive begun to speculate that this round is nothing more than attempt to make 7.62x39 less expensive to produce.

If anybody has any other suggestions to help determine the purpose of this ammunition please speak up because short of preforming performance tests on the cartridges I'm at a loss what to do with these rounds.


Edit: After further discussion on a seperate forum, it would seem that these rounds were produced this way simply because of a copper shortage in the Czech Republic during that time frame, and that it is standard ammunition. It was also mentioned that this style of ammunition was banned at one point in time because the ATF considered this to be armor penetrating pistol ammunition because someone once made a pistol that shot 7.62x39.