Long ago i use to design and swage jacketed bullets. I sold them mail order, and out of a gunshop i owned.. I made zillions of bonded core .375's long before everyone else got on the bonded core wagon....

To test your bullet, i'd drill a slightly "undersized" hole 1/2 of the length of the bullet in a piece of 2x4.. Then push the bullet in the hole "nose first" and take a hacksaw and saw the bullet through the center "lengthways". The 2x4 will hold it while you saw...

Now take a couple pairs of pliars and twist half the bullet back and forth seeing if you can get the core to pop out! You should NOT beable to pop out a core from a bonded bullet!!

I know you would NEVER have got the core out of one of my bonded bullets...

DM