rugerjunkie said:Nice to be on a forum where people know more than the ammo companies making and testing ammo. There's more than just Hornady saying what they say about the matter too. The old mini could run 5.56 because the chambers were sloppy enough to chamber a 243! Exaggerating , but all the 180 series I had were terrible.
Do whatever you want but remember things are always fine until they aren't. You can shoot 5.56 in a 223 and maybe never have an issue until that one day you load that one round into the gun and all of the sudden things aren't fine anymore.
again read the manual for your specific mini..... I looked at 3 or 4. All said 556 was fine.
The Ruger instruction manual for mini's made after 2004 which I have linked to states on page 14 that only the TARGET model cannot use 556 Thus any other mini model can run either
https://ruger-docs.s3.amazonaws.com/_manuals/mini.pdf