5.45x39mm 7n6m


#1

Did the 5.45x39mm ball cartridge designated 7N6M ever make it into general production in the USSR or Russia?

This is the M-1974 PS steel cored ball cartridge “modernized” by using a different grade of steel core that has been hardened. I’ve read that as of around 1988 and at least at factory “270”, this new cartridge was put into production.

Can anyone confirm this information or elaborate on this particular cartridge load?

AKMS


#2

I thought that was the 7N10?


#3

7N10 has a full length hardened steel core, 7N6M has the same steel core, lead plug and air space in the tip as the 7N6, only the core is hardened. I have not seen enough evidence to convince me that the 7N6M ever made it into widespread production or use, perhaps being eclipsed by the 7N10?

AKMS


#4

It can only be found out by taking apart “PS” projs. made after 1987 as the designation on the tins did not change.
As per Russian sources it was/is in service.


#5

I would like to add that according to Bolotin, the non-hardened steel core of the 7.62 mm LPS rifle cartridge was also changed in 1988 to a hardened version (obviously without any designation change).


#6

The specifications of the core of the 7N6M bullet indicate that it can be manufactured using three different grades of steel: Grade 65G (Brinell HB 229-285 MPa); Grade 70 (Brinell HB 229-269 MPa) or Grade 75 (Brinell HB 241-285 MPa). For comparison, specifications of the core for the 7N6 requires high quality carbon steel Grade 10 (Brinell HB 115-187 MPa). MPa values are variable because there are also different manufacturing standards for each grade of steel.


#7

Jochem, to my observation the Russians did not apply changes to the general designation as like the “LPS” is merely compareable to a western designation like “ball” (or others). The “LPS” is no exact type designation as for the exact design as this is then reflected in the so called “index” (like 7N6 with the 5.45 PS) and there only if the drawing number has changed - which is not the case with a change in materials used (like here).