For you hw100 owners, I see the manual recommends removing the air cylinder when not in use. Never heard of that on any other pcp. Do you guys remove your air cylinder? With all posts about leaking cylinders maybe all this on and off is the problem. Haven't had a chance to shoot for groups but I did run it on the chrony, not bad, 893 low and 903 high. Beautiful laminate stock with adustable cheek piece. It's my first in .177 caliber. Cant wait to shoot it for groups.