I bought the cheap rcbs chrono with the silly bullet shaped housing, only $120 at Bruno's. I took it to the range yesterday at 3:00 pm, 15 mph wind, 109° and direct sunlight. I didn't really expect it to work well in those conditions, but it did.. Got solid readings on every shot. Shooting a rem 700 bdl in regular 270, with 130 gr sierra btsp and Imr 7828ssc. With 59 grains powder, 5 shot average of approx. 2960 fps, 60 grains 3000, and 61 grains 3040. This is pretty much right on the published data in the Speer book. Even with the hot conditions and a hot barrel, I saw no pressure signs on the brass. Should I call it good at 61 gr or try 62 for fun?