I have been casting for years, 7 different Lee plain base bullet molds in numerous calibers all of them 2 cavity. I just bought 2 new 6 cavity Lee molds 148 grain tumble lube wadcutter and a 158 grain swc gas check design. I use wheel weights for my casting and both molds cast beautiful bullets. I use a Lee .358 push thru sizing die. I lubed the bullets first using 45/45/10 from White Label Lubes and let it dry overnight. Then I pushed the Sages gator gas check squarely on the base of the bullet and then through the sizer. Did 10 each and I was able to easily pull the gas checks off of 9 of them. If anyone has any idea why my gas checks are not being crimped well enough to stay on please let know. With the same mold in 2 cavity I used the same checks but I powder coated those bullets first before gas checking and they stayed on tight. Thanks for any advice.