Seekins Precision Havak M3 ARC Bolt Head

Seekins built the M3 generation of the Havak action around a three lug bolt head that comes out without tools, so one rifle can change bolt face size instead of buying another gun. This is the ARC bolt head for that system.

Swapping a bolt head is the cheap half of a caliber change: pull the head, fit the barrel and magazine that match the new cartridge, and the action carries over. The head itself is tool steel with a black oxide coating, which is the wear surface that takes the whole load of firing, so it gets built harder than the rest of the bolt. Confirm the bolt face size against your chambering before ordering.