My goto nitrided Toolcraft 5.56 from a solid vendor at a good price. Firing pin is the correct length for the monster bolt...
https://www.geauxarmory.com/toolcraft-ni...p-544.html
https://gun.deals/search/apachesolr_sear...obile=true
https://www.geauxarmory.com/toolcraft-ni...p-544.html
https://gun.deals/search/apachesolr_sear...obile=true

