I found a good deal on these and i wanted to see if anyone has ever used them before. Well before i go buy a case of them LOL.

T/C Thompson Center PTX Sabots

Here's what it says about them on the internet.

Power tip express bullet with polycarbonate tip
6 serrations assure rapid expansion
Polycarbonate tip improves ballistic coefficient and prevents plugging during entry
Tapered jacket and interlock for controlled expansion at conventional and magnum velocities. For .50 cal. guns. 300 grain