Ey up - holy late thread reply, Batman!
Bought two CP-1's in .177 for our club to use.
They are basic but work reasonably well. We don't bother with the magazines, just single load as it's 10m target work rather than plinking.
Found that 40 to 45 shots are always on the power, bearing in mind shots are spaced out not rapid fire. After 45 the power can drop and certainly after 50, it's game over. To that end we let members have a couple of gas only shots to get used to the trigger then 40 aimed shots. Never had any issues with running out of power with that method.
They have been in use for nearly a year, over 1500 pellets each with no reported problems.
Cheers
Paul M.
NSRA and NRA qualified RCO.