A local gunsmith is known for his finish,arctic kote (gun kote) and he bakes it on @350 degrees and I may have that done to one of my rifles but I always get a second opinion and not sure if 350 degrees will stress the metals or not,looking for advise on gun metals and heat. Thanks Greg

A lot of gun finishes require that there product be baked . 350 degrees will not harm or stress the metal. I would bead blast or parkerize before spraying on the finish.

He preps the metal before the finish and I have seen his work and it looks good, but I wanted to get educated on heat and gun metals. Thanks Greg

375,

We do a fair amount of heat treating of knife blades in salt pots. The low temp post is actually Brownell's nitre molten blueing salts. As a result, I've looked pretty hard at the temps involved for the materials used in firearms.

350F is fine for pretty much any steel that would be used in a firearm. The good news is that there will be very little distortion induced in any reasonable means of getting the materials to that temp.

For materials like 4130 and 4140, higher temps will not cause a problem but at those temps one will have to be very careful about distortion and the process should be left to a professional who is warranting their work.

I have used Gun Kote. It lasts very well if the surface is rough enough before application and very clean. (On one AR15 rifle the spents have not removed the finish from the brass deflection surfaces.) The maker suggest SAND for blasting prior to application. I can tell you that small glass beads are too fine.

Good luck!