Brass may come from different suppliers or plants or even machines. There are variances in all of it, it seems. Brass that may last many firings in your rifle, may only last 4 or 5 firings in my rifle... much of it depends on your reloading techinque, the load and the chamber it's fired in. Even the action of the weapon (i.e. semi-auto vs bolt.)
Load 'er up and shoot them... and just watch for signs of case failure as you go.
Load 'er up and shoot them... and just watch for signs of case failure as you go.