SIG Sauer Proofmarks
SIG 101 - Date Your SIG! 

 European firearms manufacturing are more heavily regulated than the U.S. industry. In the old world, and in Germany and Switzerland specifically, governments set standards on the amount of pressure gun barrels are required to withstand before bursting. 

Government authorized "Proof Houses" are licensed and regulated and as a matter of quality control and to ensure safety, all firearm produced in said countries have to be "Proofed" by an outside agency.

The "Proof House" fire special extra-hot "proof loads" through all guns to indicate their ability to withstand regular pressure loads over long periods of time. 

When a firearm has been so tested, the proof house marks it by stamping one or more symbols onto the gun. On most SIG-Sauer handguns, the symbols are placed on the underside of the slide just forward of the front of the frame and near the model P230 & P232's ejection port.

German manufactured SIG-Sauers typically come with three proof marks. The first is an ornamental crown with an N beneath it to indicate it was proofed with smokeless (nitrocellulose) powder. (The crown-N may also be stamped on the frame following the serial number.) 

The second proofmark is an "Oak Leaf" design that looks like an "8-leg 2-pincered bug". This is the proof mark for the Kiel, Germany proofhouse.  Lastly, the proof house adds an alpha-numeric (Letter / Number) code to indicate the year the gun was proofed. 

The table at right shows the letter / number to proof year index. 

American-made SIG-Sauers, namely the P229, P239 and the new SIG Pro, are proofed by SIGARMS to SAAMI specifications at the SIGArms USA New Hampshire factory. Once the guns has been proofed, a circle-'P' emblem is stamped into the lower lug of the barrel.

Proofmark Lettering

A 0
B 1
C 2
D 3
E 4
F 5
G 6
H 7
J 8
K 9
NOTE:  The letter I (as in India) is not used to prevent confusion with the Number 1 (One).

Proofmark Conversion

Stamp JB = Proofed in 1981

Stamp K9 = Proofed in 1999

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