I'm seriously considering making my own gas checks and would like advice from any of you who have knowledge about this operation. The only gas checks that I have used have been the factory made copper kind. During some of my info search I have read where aluminum works just as good as copper. Is this true? Also, there's a question about thickness of material; I have read that anything below 41 Mag can use .005 to .010 thickness material and 41 Mag and larger should use .014 to .020 thickness material. So, my next question is this: if I'm going to make gas checks for varied calibers, wouldn't it make sense to make a gas check that would suffice for all the calibers?, let's say .014 for all of them? Wouldn't .014 gas checks work with .30 caliber and .45 caliber bullets? Thanks for any advice that you can offer on this subject......Glenn