ARMOR-PIERCING BULLET AND METHOD OF MANUFACTURE OF ARMOR-PIERCING SLUGS Russian patent published in 2000 - IPC

FIELD: small arms ammunition. SUBSTANCE: armor-piercing bullet has an envelope secured in which are a jacket and a steel armor-piercing slug installed with projection of the tapered nose behind the open envelope end and overlapping the slug nose. The slug core has a structure of troostite with a hardness of 350 to 380 HB, and the external layer of the slug lateral and tail sections to depth h=(0.1-0.3)dslug is made with a hardening to a hardness of 55 to 60 HRC. The method of manufacture of armor-piercing slugs consists in cutting-off of blank from a steel rod of easily deformable low-carbon steel, slug shaping by cold stamping simultaneously of the tapered nose, central and tail sections of the slug, after that hardening of the external layer of the armor-piercing slug is accomplished by casehardening in the medium of carburizer at a temperature of 900 to 1000 C to depth h= (0.1-0.3)dslug, and the final heat treatment of the slug is accomplished by hardening and tempering of the slug external layer to a hardness of 55 to 60 HRC, and of the slug core to the structure of tempering troostite with a hardness of 350 to 380 HB. EFFECT: enhanced armor-piercing effect of bullet, reduced ricochet of slugs, enhanced capacity of process. 5 cl, 3 dwg, 2 tbl, 1 ex