Trying to make an AR-15 bolt carrier and stuck on the hardening process.
from what I can tell one approach is to start with 8620 steel, machine it, harden it, then grind to correct the deformation caused by hardening, then phosphate. From what I gather, this is the old mil-spec process.
I want to use more modern nitriding and preferably I'd like to skip the grinding step to keep things simple. I.e. harden--->machine--> nitride.
I'm not sure what HT process to use though. Any ideas?
On the other hand I see 4140 steel is used for barrels and can be hardened so is there any reason not to use that for a carrier as well?
from what I can tell one approach is to start with 8620 steel, machine it, harden it, then grind to correct the deformation caused by hardening, then phosphate. From what I gather, this is the old mil-spec process.
I want to use more modern nitriding and preferably I'd like to skip the grinding step to keep things simple. I.e. harden--->machine--> nitride.
I'm not sure what HT process to use though. Any ideas?
On the other hand I see 4140 steel is used for barrels and can be hardened so is there any reason not to use that for a carrier as well?