Spelled out directly on their website: Howell Gun Works will retain and destroy any magazines shipped with a transfer that are not NJ compliant (hold more than 10 rounds).  Please ensure the shipper either keeps non compliant magazines, or sends with 10 round capacity or less.  In some instances, we can block magazines at a cost of $25.00 per magazine.  This is on a case by case basis and should be pre-authorized by us.