Ok , first sorry if someone mentioned this already and i missed it. but#1 Isn't there a reduced FPS requirement for air rifles sold in Canada? If so you may be comparing your stats to US models. If that is the case a valve mod or pressure regulator / flow regulator mod may bring your velocities back up. http://www.bryanandac.com/Discovery.htmGun was bought in Palm Desert, California. Also there is no fps limit if you have a firearms license. Which I do.#2 What is your altitude where you are shooting Axelr?Sea level#3 i also wonder about air temperature. At the time you posted this the temps in your area are quite low. The temperature and humidity in my garage where the gun was chronographed is quite pleasant. #4 another thing to take into account is humidity. I spent a little time in Port Victoria and while it was pleasant temp wise, the air was very dense with humidity. Compressed damp air flowing across the various orifices can cause condensation and a blocking effect to the air flow. Some call this "Moisture Dampening" or just "Dampening" (technically, moisture dampening usually refers to the filtering of moisture from a system)If possible, i would try as a test of filling the rifle inside with warm dry air and then if possible shooting in a controlled environment like an indoor sooting range. And then recheck your figures. ( though i realize indoor shooting ranges might be sparse in your area)Gun was tested indoorsAnd Just as a final note. Having researched the Discovery extensively, i can say that your figures are not uncommon. Some have reported FPS figures in the 600'sI haven't seen to many reports of that but that may well be true.