Very old piece from Arnolds who manufacture SmCobalt mags which...

Very old piece from Arnolds who manufacture SmCobalt mags which while they will operate at much higher temps are considerably more expensive given cobalt inputs.

As SmCo are the preferred option DoD missile guidance, etc, Arnolds plus one other US manufacturer have been subsidised by US Govt to maintain that IP domestically.

Constantine retired fairly recently but spent the last decade trying to make a case for greater commercial use SmCo over NdFeB with limited success.

A better article from that period addressing the commercial realities:

http://spontaneousmaterials.com/Papers/Spring2013.pdf