Cold bluing a receiver and hbN in between

[GrocMax]

Have a clunker Mossberg MVP, getting a barrel done, hate the fuzzy black phosphate type finish so I sanded and polished up the visible parts and did the old Oxpho-blue deal. After drying and before carding/steel wool, throwing it in the vibratory tumbler with small 1mm ceramic bead media I used to use for hBN on bullets-

The hBN is sticking quite well, its slick as snot after carding, and its turning it an interesting purplish shade, close to TiAlN or TiCN on coated tool bits. Pretty sure it will keep darkening with more apps but the purple sorta surprised me.

Anybody tried this before?

 

[Dusty Stevens]

Do you think cold blue and hbn will keep it from rusting?

 

[GrocMax]

Gotta be better than what was on it. hBN is for the bolt travel stickyness, it was pretty rough when new, had to lap it in to get it to cycle decent.

 

[Dusty Stevens]

Is that the gun that takes ar mags? If so youre right they are ruff

 

[GrocMax]

Yep, 223 or 204R, AR mags, 1.200" diameter action, 5/8" bolt diameter, 7/8-28 barrel threads, 1.00" diameter tenon with a smooth barrel nut.

They make a 308 size version that's a little bigger.