What is the difference between these powders? Everyone seems to like TAC for a .223 but the bottle says great for .308. And the bottle of X-Terminator says something like "the best .233 powder available. Is one cleaner than the other? Is one spherical and the other isn't? I don't hear many people say they use X in .223.

Both are spherical. I believe all of Ramshot powders are spherical.

X-terminator has a faster burn rate than TAC, and would be a better choice for lighter bullets (40's).

X-terminator is close to H322 and TAC is closer to H355.

My most accurate loads in the 223 are with Benchmark, X-terminator and TAC. All are clean burning with Benchmark the best of the three.

Appreciate that!

I'm in you camp on this one!!

My most accurate loads are Sierra 50 and 52 Gr. with Benchmark. TAC is a close second,

50 grain V-max and Xterminator is my goto load for all my all my 223s. I have to admit it's easy to find great loads for the 223 with tons of combinations.

I have used TAC extensively with 75 and 77gr bullets and would say try it with heavier bullets. Accuracy can be great. Try working up in accordance with the Ramshot reloading guide. I'm going to try it with 55s, 68, and 69gr bullets and see what happens, some report good results.
I would try exterminator with lighter (to 55gr) bullets

I find Tac to be a hair slower than H335. X-terminator is my go to powder for 222/223/223AI with 40's and 50's.

I ran two string with TAC, Fed 205M, and 55gr bullets. Nosler BTs shot real well out of my heavy barrel AR.