CP means Crossman Premier. In .177 caliber, they come in "light" or "Heavy". The lights are about 7.9 grains, while the heavy's are 10.5 grain. I use the lights in my Gamo CFX, and the heavy's are the only pellets I shoot in my RWS 350 Mag.
In .20 AND in .22, they make them in just one weight...14.3 grains.
Don't confuse these with the cheap stuff you can buy in a small shiny tin...these are good pellets, sold in cardboard boxes of 1250 pellets in .177 or boxes of 625 pellets in .20 OR .22. Again, these are different than the cheap ones in the red, white, and blue tins that say "premier" on them. The advantage is that you are buying a large quantity of pellets from the same batch. They are very consistant and work very well. You cannot beat the price either.
If you shoot the CP Heavy pellets in a gun like the GAMO CFX or other GAMO guns, you WILL break your spring after 800-1000 shots. They are simply too heavy...use the lights, they are perfect. Apparently the heavier weight sets up a harmonic vibration in the spring that WILL break it. I know that sounds wierd, but it's true. Hope this info is helpful....
