Mine will hold a magnet.  Now this is only the Classic.  The Jets and original Gamemasters did not have them.

According to Jack, he put the metal rod in all of the classics.  The black section of the riser is a special plastic formula that jack developed.  He mixed it himself and poured it into the mold for the riser.  Before he poured in the plastic, he inserted the metal rod.

There are so many questions that only Jack could have answered.  The Jack Howard enthusiast lost more than a great bowyer when he passed.

I've got a Gamemaster Classic made with carbon. I believe it was Jack's first experience using carbon according to our correspondence. 66# and too heavy for me anymore. It's a VERY fast bow and I might be talked into letting it go.

Hey Charlie.

Just sold a 49# Jet.  The buyer will be calling you about extra strings.