I think this is a bug or glitch with the C4 stats on BF4. I run C4 with Support every day I'm on and get tons of C4 kills but on Battlelog it says I only have 5 C4 kills. It's been like this since the first day BF4 came out. I have no idea how many C4 kills I actually have because of this but I do know that I average 5 C4 kills a match. Please fix this.
the Battlelog forum, you can't report such bugs in here. We can't fix them. Please go to the official Battlelog forum for Battlelog-support or bug-reporting. :-)