Tac for 50 and up, X-Terminator for 50 or less. Good accuracy and velocity; easy metering, hundreds of rounds between cleaning. IMR 4895 will work if I don't have Tac or X-Terminator but doesn't meter as well and requires more frequent cleaning.
X-Terminator usually beats TAC for accuracy and velocity up to 69gr, in my experience; Ramshot's 5.56 data shows this too.
For 50-55gr, XTerminator is so much better than everything else, it shouldn't even be a question. In my "humble" opinion.
