I do not think that. What I meant to say is on the smaller caliber like .224 and .243 I use the aluminum flashing as it's thick enough for the gas check shanks that are on bullet which is determined by the mould. On the larger calibers the flashing is too thin and after you applied it, it's not the full diameter you size too. I don't believe in doubling up on the flashing. So I obtain thicker aluminum material for those larger calibers. I hope that I have explained it. Look at all the brands of moulds that are out there. I don't think there is a standard for what thickness gas check they use.