I have 2 mags that came with my US 510 and both have cracked on the clear plastic. The plastic is now in 4 quarters on each. I'm wondering if the new ones aren't as strong as the older ones with the yellow plastic? Has anyone had a similar issue?

Hi, does anyone know the difference in cocking effort of a .177 Pro Sport in FAC vs 12 ft lbs? Can't see it on their website.
Cheers