Okay, as of 7:00 PM tonight, I am a SIG owner.  

I got a red box (pre-owned) P220 from someone on the EE here.  I'd post a pic, but, well, it looks like an average P220.  

The serial number is G228XXX.

Am I correct in assuming the slide is carbon steel (as opposed to stainless)?

Is it blued, or is it this "Nitron" finish?

Any way to tell when it was manufactured?  

Thanks...

If it has double roll pins (one inside the other) going laterally through the slide in the vicinity of the grasping grooves, it’s a two piece slide and is made from carbon steel and has either a blued or K-Kote (polymer) finish.

If it has a solid pin going through the slide, it should be a one piece milled, stainless slide with a Nitron finish (unless somebody replaced the roll pins with a solid pin – which should never be done!).

You can also easily check to see if it’s a two-piece slide by removing the slide and seeing if the breechblock is a separate piece or an integral part of the slide.

Does it have proof marks on the bottom front of the slide (near the muzzle)?

Quoted: If it has double roll pins (one inside the other) going laterally through the slide in the vicinity of the grasping grooves, it’s a two piece slide and is made from carbon steel and has either a blued or K-Kote (polymer) finish. If it has a solid pin going through the slide, it should be a one piece milled, stainless slide with a Nitron finish (unless somebody replaced the roll pins with a solid pin – which should never be done!). You can also easily check to see if it’s a two-piece slide by removing the slide and seeing if the breechblock is a separate piece or an integral part of the slide. Does it have proof marks on the bottom front of the slide (near the muzzle)?

Thanks for the info.

Double roll pins... check.

Separate breechblock... check.

Doesn't look like a polymer finish, must be blued.

No visible proof marks on the slide, which BTW is marked "made in Germany."

Quoted: ...No visible proof marks on the slide, which BTW is marked "made in Germany."

SIGs can sometimes be confusing with such markings.

The “Made in Germany” can simply mean the slide was made in Germany - while the actual pistol was assembled here in the States.

If the pistol had been assembled in Germany, it would have been proofed.  And then it would have proof marks, to include a coded proof date, which essentially would tell you the date of manufacture.

Note that the original SIG blue finish is not very durable so don’t be surprised if it wears pretty easily.  Also, the carbon steel slide can rust fairly easily if not taken care of.  

Quoted: If the pistol had been assembled in Germany, it would have been proofed.  And then it would have proof marks, to include a coded proof date, which essentially would tell you the date of manufacture.

Ah, thanks.

Of course, I don't need to know when it was made.  Perhaps if I get real curious, I can call SIGARMS.

Quoted: Note that the original SIG blue finish is not very durable so don’t be surprised if it wears pretty easily.  Also, the carbon steel slide can rust fairly easily if not taken care of.

I've heard that.  Thanks.

By the way, I shot it tonight.  100 rounds, Winchester White Box.

No failures, very accurate, shot to point of aim.

Very nice.

Good luck with that P220. I'm sure she'll serve you well.
By the serial number on your P220, I'd guess that it was made somewhere around 1994 - 1995.
I have a "KC" (1992) code P220 with the serial number starting at G201 and a P220 that was made in 1996 that starts with G262.
You can email or call Sig CS with your serial number and they will tell you the date of MFG.