HP
Here is my attempt to explain...
Orignally the 250's shock waves came with a Harvester Sabot
Then TC had MMP make one for them - it was to thick (HPH-12)
Then MMP changed the sabot to HPH-12 a thinner sabot...
At this time MMP is also making a Green HPH-24 (thin) Green sabot for TC (44 caliber) but can not sell it to the public... I tried to order some last week...
I also am guessing that two of the sabots are black and I am thinking the orginal Harvester was red - just guessing...