Possible to both salt bath nitride and chrome line a barrel?

[chucky2]

Seems that chrome lined barrels are phosphate covered, not as corrosion proof as SBN (aka Melonite, QPQ, I'm sure I'm missing some). Chrome is supposed to be better for longevity. Curious if, and I know it'd add cost, be possible to both salt bath nitride at least the exterior of a barrel so it'd have superior corrosion resistance, but have the bore and chamber chrome lined so as to be the longest lasting?

Happy New Years!

Chuck

[lysander]

While it is possible to chromium plate over nitride, you cannot use acid to etch the part in preparation to the chrome plating, that only leaves mechanical etching methods. And these methods are too imprecise for a rifle bore.

Going the other direction is also possible, masking the bore with copper plating, gas nitriding, stripping the copper off and chromium plating the bore, but this is a lot of work for minimal gain, with the possibility of missing areas.

[Hohn]

If you are worried about rusting the outside of a barrel before the inside is worn, don’t. The outside isn’t a functional surface and any number of preservatives over phosphate can provide reasonable corrosion resistance.

I’m partial to the wd40 specialist long term corrosion inhibitor for corrosion prevention. I use it on external surfaces primarily but it can be used in bores of barrels susceptible to rust.

[Stickman]

Seems that chrome lined barrels are phosphate covered, not as corrosion proof as SBN (aka Melonite, QPQ, I'm sure I'm missing some). Chrome is supposed to be better for longevity. Curious if, and I know it'd add cost, be possible to both salt bath nitride at least the exterior of a barrel so it'd have superior corrosion resistance, but have the bore and chamber chrome lined so as to be the longest lasting?

Happy New Years!

Chuck

For a barrel already manufactured? No.

I know a company that had SS barrels QPQ treated, but there just wasn't a cost benefit involved, so the project was canceled after one run of them.