Named item death message not showing

I play a type of gamemode known as TNT minecart pvp, and there is a method called Xbow, where you place a rail, TNT minecart, then flint and steel the ground and shoot through the fire, and it will explode the TNT minecart. The TNT minecart community has figured out that, upon naming the crossbow, it will say <Player name> was blown up by <Player name> using [Item name]. However, when you activate the TNT minecart with a flame bow, even if the bow is named, it will only rarely (From the low chances I have received, roughly 1/100) show the item name as <Player name> was blown up by <Player name> using [Item Name], and will say just <Player Name> was blown up by <Player Name> the rest of the time. A fix would be to remove the Xbow showing item name, or to add the item name to the bow.