SD9 Dimples Question

[ADP3]

I have three SD9 VEs. So I guess it's obvious that I like the gun. As I was cleaning them after a family range session I noticed something for the first time. On the forward/underside of the slide there is a milled recess in the shape of a square with rounded corners. Within the recess there are one to three "dimples" milled in. I assume the recess is to reduce slide weight. Does anyone with a .40 S&W SD know if there slide has the milled recess? And does anyone have an idea what the "dimples" are for?

You can see from the illustration I made what there placement is. I was curious if this is a factory code or milled out for more weight reduction. Two of my SD9 VEs are only three serial numbers apart but they have a different dimple pattern. Let me know if you have any ideas on this.

Best Regards,
ADP3

 

[SteveFi]

i have read that is a factory code related to the milling or cnc machine used but I cant give you any references or confirmations

 

[EBK]

My SD40 VE does not have the dots however just below the squre your dots are in is a pattern similar to this
=
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[J Rich]

If I'm not mistaken it's factory code. Like a second serial number if you will. My Sigma has them, but on more of a checker board pattern if I remember correctly.

 

[KiD's SD]

i have 3 dots but not in the square sd9

 

[shawn mccarver]

I have three SD9 VEs. So I guess it's obvious that I like the gun. As I was cleaning them after a family range session I noticed something for the first time. On the forward/underside of the slide there is a milled recess in the shape of a square with rounded corners. Within the recess there are one to three "dimples" milled in. I assume the recess is to reduce slide weight. Does anyone with a .40 S&W SD know if there slide has the milled recess? And does anyone have an idea what the "dimples" are for?

You can see from the illustration I made what there placement is. I was curious if this is a factory code or milled out for more weight reduction. Two of my SD9 VEs are only three serial numbers apart but they have a different dimple pattern. Let me know if you have any ideas on this.

Best Regards,
ADP3

I had understood the dimples are the manufacturer's code. At the time it was explained to me, I was asking about M&P pistols, and it was said that some slides were machined by outside vendors. Thus, I assume it is a code to tell who made it. Whether it relates to which machine at S&W or which outside vendor, I do not know.