Your targe looks great!

In the couple I have made, the wood used decides if pilot holes need to be drilled or not. The first one I made I used oak plywood and had no problems hammering in the tacks. The second one was regular ol' ply wood and pilot holes were needed.

I highly recommend the 1/2 inch oak ply wood used for cabnent making. Its easy to cut and takes the tacks really well.