Looking to buy some brass inserts for my 250;s, I can't seem to find what size they take. Anyone know?  Are they the 5/16's

Yes they take the standard 5/16" inserts,they may fit alittle tight and you may need to sand them to fit.Most of the 5/16" carbons have a .246 ID and I believe CX have a .244 ID.I like to sand brass inserts to fit and that gives them some teeth for the epoxy to hold them in.

Awesome! THanks !