I take photos at sporting events. Getting hard to get my Nikon D7100 in as "professional" cameras and changeable lenses are not allowed. I do have a Nikon P600 which I use, but the focus is slow and the shutter blackens the view and I cant follow the action after taking a photo. The Nikon P900 is too big. The Sony A6300 is perfect except the lens only goes to 55mm and I need at least 300mm. What is the best zoom camera (similar to the P600) with no interchangeable lenses? Lumix? or other. Any help is appreciated.