Just got this answer back from Winchester.
Thank you for contacting Winchester Ammunition.
We appreciate your business and we look forward to providing you with the same high level of customer service and support you have come to expect from us.
Here is the initial question/comment you submitted to Winchester on 11/13/2017along with our response.
Question:
Does Winchester manufacture their own brass for 9mm?
Also, why two different FONTS on headstamps
W I N 9mm & W I N 9MM?
Answer:
Dan,
Yes we make our own brass. We have multiple head-stamps as we have multiple machines that run that caliber.
Best Regards,
Technical Services Dept.
Thank you for your feedback and for being a valued Winchester customer.
Sincerely,
Consumer Service Department Winchester Ammunition