Also, you can substitute primers if you know what you are doing. But if you just start out reloading ..... it is probably saver to stick to published recipes.
Here is an article that explains a bit more about primer substitution ....
http://www.armbrust.acf2.org/primersubs.htm
In the example that Tom Armbrust used and tested ..... when he substituted a Winchester primer for a Cheddite one, the pressure went only up by 870 psi.
3macs1, the Cheddite primer issues that you had .... when was that .... how many years ago? I am just wondering? As far as I know the commercial Challenger ammunition today is using Cheddite hulls and primers ... and many people shoot those by the flat ...
So, I am wondering if Cheddite might have resolved those issues?
I have been reloading primed Cheditte hulls for a couple of years now .... and have not had a problem yet with them.