I have a hill mk3. It seems to work fine but I am a springer shooter who's dabbling in pcps. Why does the pump feel heavy when pulling it upward? Is it supposed to feel that way? When pushing down nothing seems hard till like the last 2-3 inches. Is that normal? I do about 40 pumps and take a time out as to not over heat it. In pumping up a urban from about 1500psi to 3000psi and it takes about 120 strokes. Is that normal. Thanks in advance