I bought a 40 cal. S&W stainless when they first came out many years ago. I decided to polish all the flat surfaces only. It turned out extremely nice. It took several hours to do it but was well worth it to me.
I used masking tape to cover areas I did not wont polished and replaced it as needed. lowes or Home Depot had sticks of polishing compound one of those was made specifically for stainless steel. I also got a stick of jewelers rough to complete the miirror finish.
I have not polished a Kahr before, but if it is stainless steel it can be polished.