Saw this on a used P226 LDC II stainless pistol and have never seen this “deer antler” type symbol. Anyone know what this represents?

Stag Horn proof mark. Used for the Ulm proof house I believe. It indicates that it was proofed there.

Thank you Cslinger for this detail. Learned something new today. Mark

Yes it is. See it a lot on HKs. Btw, that's surprising to see on a SIG, since the Kiel proofing on SIGs are done in house.

Ok guys - Please educate me a little more on this topic.

When this “proof mark” or any other identified proof mark is on a handgun does this mean that the barrel or the entire gun is sent to a specific facility where the entire gun or barrel goes through a complete re-inspection against an identified specification?

Does SIG or HK send every pistol they make to be proof checked or only random samples from a lot?

Thanks Mark

Every single gun that is assembled in a CIP country has to be proofed, by law. No such thing as random batch testing. Once passed the proof testing, the complete gun's major parts (frame, slide, barrel) are then received the proof marks.

Old and current proof marks can be found on CIP home page:

Old proof marks

Current proof marks

ETA: Too bad CIP has nuked their old proof mark pages for individual CIP country. But, check the link below for the old proof marks.

https://pdf4pro.com/view/proof...a-museum-3a2e22.html

Thank you Q for this extra detail. I did not realize this was a requirement. Thanks again for this educational session. Greatly appreciate you and this forum’s members.

While proof marking doesn’t necessarily mean a better firearm many of us sort of “geek out” on them so to speak. I like my firearms with various proof marks.

Antler is the proof mark for the Ulm house.