AFB accelerator pump check ball keeps sticking.

A larger ball is a lot simpler solution than laying hands on a tool to clean up / correct that seat. What are the odds that a correct angle stone would be found in a 4 dollar dremel kit? Grind that angle on a drill nose?
Professional carb reman' shop would use some type of tool to clean up the seat so the OEM ball fits and works. We do whatever we can with what we have to work with.