You bought 1000 GC bullets with out the gas checks? They have the heal for it , but missing the actual Gas Check? The gas check is keep hot gasses from melting the lead alloy on the base of the bullet, if your loads do not generate enough pressure depending on the alloy used you should be OK if you stay under 1200 fps. When I bought GC designed bullets they always come with the gas check other wise the company will sell you a plain based bullet. If they are a gas checked bullet design and do not have the gas checks already on them, you would need to purchase the gas checks and then a die and press to put them on with. Good Shooting and Good Luck