380 acp from .233 Rem?

[Bcwitt]

Also, I am pretty sure handgun brass is a softer alloy(higher copper content) then 556. I think such a case would Crack very easily. Take an oxy/ace torch to a few specimens & you will see what I mean. 22lr & low pressure handgun brass wets out very nicely (almost like a good brazing rod) rifle brass does not.

 

[GravelRider]

I use it but take it as a set of helpful suggestions of what to look for, not the final word. Example being 9mm Makarov. The conversion is a lot less complex than the guide suggests.

Good to know. I've only ever converted .223 to .300 Blackout, and that isn't even in this book!