Laggy duplicatemovieclip

Yeah, it seems to lag after making a lot. I’m trying to make it so you’re shooting bullets, but with each bullet it lags worse. The duplicate movieclip it being removed, AND replaced. I don’t know why it’s lagging. All the bullet is is a line.
It used to be only shooting one bullet at a time, and it didn’t lag then

Should I go back to the old way I had it?
Does it always lag after a lot of duplicates?
Does it not delete the actions that are in the duplicate movieclip?

answering one of the above would help me