Is the gas chamber chrome lined?

[PVBoom]

With respect, that sounds like a lot of money and effort for something that is unlikely to be of any benefit.

If its of no benefit why are bolt carriers coated in NiB or TiN?

Its considered to reduce wear, increase lubricity and make cleaning easier.

As for the cost, he charges $155 for an entire pistol, which is a lot more work in terms of disassembly and assembly.