UPDATE: Today I did another experiment, I counted the shots to see which ones missed and which ones hit.
I first pushed a very soft rolled up tissue through the barrel in an attempt to clean it, it came out slightly dirty.
I loaded the mag with 20 BB's and I fired the first 15 singularly and marking on the target where each shot hit. Shot # 6 missed completely (and sounded different). I then fired 5 more shots, one directly after the other, they all hit. I then discovered that I had 1 BB left. Which would make 21 shots, but I know I only loaded 20 BB's and the barrel was empty before I started. This leads me to believe that sometimes the BB is not being loaded correctly.
When I get more time I will attempt this experiment again to confirm my findings. If it is the case, that the BBs are not being loaded each shot, what would you recommend?
I'm an English guy, who's married to a TW gal, and hangs out with a bunch of expat Canadians who also live here in TW.