I'm not really in a place whare I can check my 75 right now, but that gap does look a little big to me. Might want to check the over all lengenth (OAL) of the snap cap against a real round that was factory loaded from a reputable ammo manufacturer. It could be that your snapcap is out of spec. Also, check the condition of the lugs on the bbl and the groves inside the slide to make sure they are clean. If they aren't, it might not be locking up completly. (I am assuming that this is a used gun by the price. NICE price by the way. You won't be disapointed.) As someone else said, check with the CZ Forum. Also, you might want to send an email to Mike at CZ-USA. He is the master gunsmith for CZ and knows them inside and out. Check on the CZ website for his email address and send him the pic.
Good luck and shoot the heck out of that thing. You'll love it! Best gun in the world.
Peace out,
Calhoun