Rifling is moot. How did he check the chamber? If it's dimensions are not KNOWN to the .0001",you have nothing. Having brass is great,but it's dimensioning needs correlated to the chamber's particulars,before you blow yourself up. Hint.

I'd simply Cerrosafe and KNOW,then weigh options from there. What receiver is it? Who's barrel? What do you hope to do with it? What contour? What do you have for dies?

I do NOT shoot anyone else's ammo,ever.

Hint..................

Brad says: "Can't fault Rick for his pity letting you back on the fire... but pity it was and remains. Nothing more, nothing less. A sad little man in a sad little dream."