Hi all,

One of my 320c barrels has “G21” stamped on the left side of the hood, whereas my other one does not have any marking on the left. I’m just curious what the G21 means, if anything.

Thanks!

Glock 21 barrel?

At one time SIG Classic line pistol locking inserts were marked in ways that were obviously intended to indicate what guns they were for and whether they were MIM or the previous machined types. They also changed the coding over time. I always assumed that practice was to make it possible to easily ensure that the right version was used when assembling a gun because different types might not be easy to tell apart.

I have seen various markings on barrels and slides, and with the proliferation of different P320 models, I assume they are for the same purpose. Or alternatively, on some parts like barrels they could be lot numbers to permit identifying which machinery was used to produce them in the event a problem occurred.

I think I recall seeing a “G21” mark on one of my barrels. I may check (later) to see if I can find it.