Ive shown you how its done, twice. The results are on the clubs notice board. Its very difficult to obtain 50s through streaming eyes and with cotton wool buds up your nose.
As for CO2 filling. Its 4.30am and Im still experimenting. Ive managed a personal best of 272g on a FWB short cylinder (empty weight 225g) This was achieved by putting the cylinder into a fridge (-2 degrees) for 17.5 minutes and then filling with the cylinder pointing in a northerly direction.......