100-1000 USD depending on specifics
200-1000 usd
That depends on which 5.56 round you had in mind. The original M193 cartridge used a 55 grain projectile. The current M855 and SS109 NATO standard cartridges use a 62 grain projectile. The M196 tracer (which complimented the M193 ball cartridge) uses a 54 grain projectile. The M202 cartridge used a 58 grain projectile. The experimental XM287 and XM288 cartridges used a 68 grain projectile. The M856 tracer (which compliments the M855/SS109) uses a 64 grain projectile. The M995 armour piercing cartridge uses a 52 grain projectile. The Mk. 262 Mod. 0/1 cartridge uses a 77 grain projectile.