I use 55 & 30 gallon plastic drums for planters,rain barrels, and many other things. I have not used them for warms yet.
The problems I see is making sure the drums are clean of chemical, but for using it for worms. You can cut it in half vertically or Horizontally. You could lay the drum down & cut only the top 1/3 of the drum from top to bottom, this will give you higher sides then cutting it in half vertically.
We would like to see photos. I use a sawzaw.

I posted some links in your other post at the link below

Here is a link that might be useful: Answered over here

The main problem would be the handling.

A half drum full of worm compost would be damn heavy. With drums, you wouldn't be able to easily set up any kind of layered system to seperate the worms from the compost and drawing off the worm tea in a controlled manner would be a mission.

If you really want to go DIY rather commercial, then use simple plastic tote bins that are easy to set up as layers, because they are tapered and easy to nest.

They are the only real answer for a neat and tidy set up that doesn't mess up the entire area whenever you need to work with your worms - see the following web page for directions to make a simple but effective worm farm.

Here is a link that might be useful: DIY Worm Farming