I'd ask Ullie because he would be the most likely to know of the serial #s or timeframes of manufacture to watch out for. I can tell you that mine is an october 2010 manufacture JT019XXX, and has had no problems. As for when the 'bad' batches were made, I haven't been around this forum or owned enough 556s to know. That came in real handy when I got my great grandpa's.22 made in the '30s. I don't know why they don't have a tool on their website like winchester does where you can type in your serial #, press enter, and it gives you the date of manufacture. But I'm pretty sure you'd rather just look at the sticker on the end of the hard case it came in.

You can call in to SIG and pay $50 to get a 'SIG official date of manufacture certificate' for it:roll. SIG Sauer with the serial number and see if they. To shotgun barrels in an early stage of manufacture. Home » Articles » SIG Sauer Proof Marks and Date. Sig p229 date of manufacture, sig sauer p220 german build date, sig sauer p229 date codes. Sig manufacture by serial number 228, sig p220 serial number dating. Only a date code can tell you the year of proofing. Serial numbers aren’t always truly representative of the chronological order of a firearm, but they can sometimes get you close. It’s impossible to decode a SIG serial number to determine when it was proofed, although you can try to locate the range of your SIG’s serial number in this list to approximate when it was made, or call SIG Sauer with the serial number and see if they have any info in their system. Also has serial number on barrel, but NOT on the slide. AD274XX-?/?-9mm Nitron had Hogue grips when I bought it used.

Sig p229 year of manufacture