What parts were blued (if any) on the Quality Hardware M1 carbine?
What parts were blued (if any) on the Quality Hardware M1 carbine?
All the Q-DA (very early mfg.) or DA-Q recoil plates I've seen were phosphated...
I don't think recoil plates on QHMC carbines were ever blued. Bolts, firing pins, extractors, and various pins were blued or DuLite finished. Some mag catches, hammers, sears, and hammer spring plungers were blued. Don't know if it is true for QHMC carbines but I think some type 1 barrel bands and front sights were blued.
Maybe your recoil plate had worn finish on top and someone used cold blue to put finish back on it.
Mike is right. Early barrel bands and even receivers were blued like with Inland.