In general that policy is correct. However, if you are getting what you need that is available at Clark Bros,, I think you are ok to shoot there.

I shoot a muzzleloader so I figure if I am buying my primers, powder and any other items I need that they have in stock, I am not abusing their policy by buying my bullets wherever I can find them. Some of their stuff is overpriced (Blackhorn 209 is $40 a bottle!) but I consider it the price of using the range, since most ranges charge at least $10 an hour.