The cheapest shell of all is to buy an army ruck sack from an army surplus store.
Step2
Buy playsand and roll it into a ball that will fit down into the bottom of the shell. Roll the ball in many layers of trash bags to keep it from splitting and pouring sand everywhere. Roll the wrapped ball to the bottom of the shell.
Step3
It's a good idea to first buy a piece of foam from a crafts store to line the inside of the bag. This will keep the bag from getting lumpy.
Step4
Next use old rags, clothes or pieces of foam to pack the bag tightly. If the bag is not heavy enough from the first ball now is the time to roll another ball of sand into the bag. Pack the filling materials in tight so that the bag doesn't get dents in it as it is used. Tie or zip it up.
Step5
Hang the bag using a heavy gage chain and ceiling hook that can hold the load. Make sure to screw the hook into a beam in the ceiling that can bear the weight. Get the chain cut to length so that the top of the bag lines up with your sight line. You should be able to punch strait out and hit the bag.
Step6
Have fun with your new inexpensive punching bag. Remember that over time the materials will settle and you will need to stuff more packing into the top of the bag. Other than that it should be ready to go. Have a great workout!
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