We are not ones to push a light filler but this is like nothing you have seen. It’s not extreme light weight but is less than half the weight of a regular fill and about 1/3 the weight of a heavy fill. This is not the squishy foam stuff that wobbles like crazy and turns to dust. This filler is made up of firm, small particles and has a chalky feel that allows it to lock up really well. The firm particles do not give under the weight of the rifle so you get the stability of a heavy fill with 1/3 the weight. This is guaranteed to be more effective than any reduced weight fill (and possibly more effective than your current standard fill).
The large size should be sufficient to fill a full size barricade bag.