You can also go for spray & pray and buy a drummag. Fill the mag with about 2500 bb's and spray spray spray!
The Drummag is a magazine that can hold about 4 to 6x more bb's than a standard Hicap.
If you really want to be able to give suppressive fire so your team or squad members can push through to win the objective, you really need a Drummag. Because of the large capacity bb's a drummag can hold, you can spray a lot so the other party will have to take cover. This way you create the perfect moment for your team members to push through.