The only 5.45 rifles with keyholing issues are the Century Tantal and few of the S&W AR uppers. Century even went so far are to produce Tantals garanteed to keyhole with something by use different barrel options; one barrel will keyhole with commerical ammo, the other with surplus. With S&W it seems to be more isolated and possibly just a bad barrel.
Tantal by Interarms or other builds using orginal barrels have no issues. Bulgarian `74, both new production SLR105s and kits with orginal barrels don't have issues. Russian Saiga SGL-31 have no issues. Romanian SAR-2, WASR-2, WUM-2, Romak-2 have no issues. If it was built in a com-block country it's gtg.