Using a punchbag wall bracket?

If you can, get a longer one, or try not to let it swing so much. A heavy bag/punchbag isn't supposed to swing anyway, obviously it moves abit as you hit it but not swing into the wall. The �15 pound one might be a bit to small/short. If its possible, go to a proper boxing/martial arts sports store, they'll have everything you need, and any answers you need answering.