I am considering having the Slide on my Shield milled for a reflex sight. Since this is my EDC, I don't want to be without it, for 4-6 weeks (or whatever it takes) I am thinking of buying another Shield and sending the Slide to be milled and still have an EDC, and then probably selling the extra gun afterwards.
The question is, are there matching serial numbers on Slides and frames, or just the frame has a serial number?