MK25 internals

Not all were. And SIG started phasing out the phosphate parts a while back and replacing them with what they call "Super Blue" (whatever that is). The "Super Blue" is supposed to be more corrosion resistant than standard "blue" parts, but the finish is smooth, and generally produces a smoother action than the matte phosphate parts. When you order parts online, you will occasionally see a choice of a standard "blue" finish or the new "Super Blue".

Thanks for the heads up ..The super blue sounds like a better way to go,,The parts hunt is on

peter36330 said:

Thanks for the heads up ..The super blue sounds like a better way to go,,The parts hunt is on

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Internal barrel is still phosphate coated.

gwangju said:

Internal barrel is still phosphate coated.

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I believe it was also supposed to be chrome lined as well?

Yes. The MK25 barrel was phosphate coated on the outside and hard chrome lined on the inside. I have not seen a MK25 barrel that was "Super Blue" on the outside and chrome lined.