Use a good bullet and the 223 is a fine deer round. I imagine you will be shooting factory ammunition...federal loads a 55gr Barnes TSX that'll whack & stack. They are around $30/box, but a guy can always plink around with the cheap stuff and save the pricey stuff for a quick sight-in and hunt. Even though much cheaper soft points will work, I would go ahead and get a box of the good stuff to give yourself an edge.

If you fancy the swat rifle after toying with it, though, go for it.