JP Barrels accuracy

[Klem]

but that black teflon is outside; however, what coating is inside?

(for example Faxxon offers inside and outside nitride salt bath coating, which i assume helps from corrosion greatly)

You can buy anti corrosion protection from manufacturers like Zerust which will end up cheaper than chemical coatings. Any chemical coating on the inside of a match-grade stainless barrel is likely to stuff it up anyway. By all means coat the outside in whatever you want but my advice is to leave the inside pristine and just clean and oil as normal. The inside of the barrel is the gun.

I use corrosion prevention cord when not in use.