▁the ▁R PK ▁( ). ▁ ▁He ▁also ▁developed ▁the ▁general - pur pose ▁PK ▁machine ▁gun ▁( ), ▁which ▁used ▁the ▁more ▁powerful ▁ 7 . 6 2 × 5 4 R ▁cart ridge ▁of ▁the ▁Mos in – N ag ant ▁rif le . ▁It ▁is ▁cart ridge ▁bel t - f ed , ▁not ▁magazine - f ed , ▁as ▁it ▁is ▁intended ▁to ▁provide ▁heavy ▁sust ained ▁fire ▁from ▁a ▁tri pod ▁mount , ▁or ▁be ▁used ▁as ▁a ▁light , ▁b ip od - mount ed ▁weapon . ▁The ▁common ▁characteristics ▁of ▁all ▁these ▁weapons ▁are ▁simple ▁design , ▁rug ged ness ▁and ▁ease ▁of ▁maintenance ▁in ▁all ▁operating ▁conditions . ▁ ▁Appro xim ately ▁ 1 0 0 ▁million ▁A K - 4 7 ▁assault ▁rif les ▁had ▁been ▁produced ▁by ▁ 2 0 0 9 , ▁and ▁about ▁half ▁of ▁them ▁are ▁counter fe it , ▁manufact ured ▁at ▁a ▁rate ▁of ▁about ▁a ▁million ▁per ▁year . ▁Iz hm ash , ▁the ▁official ▁manufact urer ▁of ▁A K - 4 7 ▁in ▁Russia , ▁did ▁not ▁pat ent ▁the ▁weapon ▁until ▁ 1 9 9 7 , ▁and ▁in ▁ 2 0 0 6 ▁account ed ▁for ▁only ▁ 1 0 % ▁of ▁the ▁world ' s ▁production . ▁This ▁arm ▁became ▁famous ▁due ▁to ▁its ▁reli ability ▁in ▁the ▁most ▁extreme ▁clim atic ▁conditions , ▁function ing ▁as ▁perfectly ▁in ▁the ▁desert ▁as ▁in ▁the ▁t und ra . ▁It ▁is ▁in ▁official ▁use