so I was looking at an add in the classifieds for a P239 and in the seller's description he said he had both blue and phosphate coated magazines....

I realized I also had both for my P239s in 357 sig and was just wondering what the deal was with this?

Are you looking for an explanation for what “blue” and “phosphate” refer to, or why P239 magazines have different finishes?

I think I understand the two coatings... just wondering why two different coatings were made... the reasoning behind it.

wondering if the blue are mec gar NOS units?

not that I have seen every mag they ever made, but all the mecgar mags I recall seeing , and owning, are blued or stainless

I can’t be certain why there are two different kinds of finishes, but over the years I’ve seen SIG magazines with three types: Phosphated, blued (of some sort; possibly not the traditional bluing), and bare stainless. Mec-Gar also makes magazines with an “antifriction” (ILAFLON?) coating.

SIG has a history of changing details about its guns, and I suspect the different magazine finishes are just one example. Why? Cost, “tactical look,” different suppliers, ….

Just to throw this in... I carried a Ruger LC9 pro for a while (one summer) and one of the reasons I switched to Sigs for carry was the Ruger rusted...not just the slide on the gun but the magazines too.... So far none of the Sigs I've carried.... P290 & p239 have started to rust; gun or magazines....

The polished blue magazines are what came with Commercial P239s

The phosphate coated magazines are what came with Agency P239s



These days I only carry the phosphate magazines because I am using the Agency 8 shot mags instead of the civilian 7 shot magazines