The CW-21B carried 2x fusalage mounted .50 cal guns with 1x .30 cals in each wing, not too bad. This was the latest and most used model. That model also used 1,000 hp R-1820-G-5 engine and had inward retracting gear opposed to the rearward retracting gear of earlier versions. (same mechanism as the P-36/P-40) With a takeoff weight of 4,500 lbs it had a wing loading of under 26 lb/ft2 and power/weight of over .22 hp/lb
Though the initial climb rate was probably very good, the 5,000 or 4,500 ft/min sometimes quoted seem a bit excessive, and 3,500 ft/min is probably a much closer value, which is still excelent. (similarly the A6M2's climb rate is sometimes given as 4,500 ft/min, it was more like 3,100-3,500 ft/min as well, similar to the Ki 43-II) The higher figures are probably with zoom. (or for the Zero, maybe in US tests with 100 octane gasoline)