I'm thinking of trying the TC Shockwaves & XPTs in my Knight DISC .50 cal w/ 100 gr. Pyrodex pellets. Anyone used either of them and what are your thoughts?

Both good bullets you need to shoot them and see how they group in your rifle.
The Shockwave bullets are made by Hornady as well, They are called SST bullets here is a link showing how well they work from a forum member

http://www.deerhuntersclub.com/forum...e-hornady.html

For many years i've used the 250 grain Shockwaves and the 240 grain .430 XTP in different guns. There is little difference in the effectiveness of these bullets: Put either where it is supposed to go and it will do a good job. For longer shots i prefer the Shockwaves.

Those two bullets have worked very well for me; taking about 35-40 whitetailed deer and more wild hogs than i can count.

Oh by the way some feel the XTP is a better bullet for deer sized game

SWs come in 250 and 300 gr and the XTPs (at least the .429") come in 240 and 300 gr. For deer the XTP would get the nod from me. But for deeper penetratin as some members suggested, the SW would be better.
You can also try a soft point bullet like the Sierra .4514" in 300 gr. But that may be too much bullet for deer.

Hmm...the SST and XTP are my 2 main hunting bullets, though I tend to opt for the SST.

A Knight Disc shooting two pyrodex pellets with a 300 grain Hornady .452 XTP with a MMP HPH-24. This was yesterday. I would hate to be the animal being shot at with that load. And I am sure there are some of the ballistics experts in here that could even give me some numbers on velocity, etc...

Been using the 240 grain XTP's in my TC Omega since I bought it. These bullets do a lot of damage on deer.

I used 250 gr XTP for years then switched to the Shock Waves. I use the yellow tip for practice and the Blue tip for hunting.
My judgement of effectively :
The XTP at close range on broadside shots with a powder load of 100 grains or less they are very effective, at long range or on long angle shots not so effective, they lose a lot of velocity and foot pounds of energy at long range and they shed the jacket and sometimes break up so long angle shots are questionable.
For larger game or long angles or long distance there are better bullets.
The yellow tip Shock Wave retains it velocity and energy much better but is very similar otherwise.
The Blue tip or bonded Shock Wave retains the same velocity and energy as the yellow tip but is much tougher it penetrates well enough for bigger game and holds together like the Deep Curl.I use the yellow for practice and the blue tip for hunting.
A picture is some times better than words. This is the last deer I shot with the blue tip, I was waiting for an other buck as I had gotten one with a bow but she had a broken leg and I felt I needed to do something about that. We only get 3 tags in my zone where my hunting property is this year and I really did not want to use one this way.
The picture is the inside of the rib cage on the side the bullet exited. I would not shoot them in the meat with this bullet. Would you believe she only went a couple of steps.

Going to use 240 gr XTP mags (.452) for the first time this weekend in my Omega. Used Shockwaves in past and had great results. I ran out of Shockwave and had plenty of XTPs, and they shoot just as good, so I am trying them this season in IL.