Here is my Lee LoadMaster press and the removable/portable bench mount I made for it.
The base is 1/2" plate, and the support is 2" box tube. I have a bracket that I can put in my trucks receiver hitch so I can do test loads in the field.
On the brackets are set screws/bolts so I can adjust the height or distance from the bench.
You have to lean into it really hard to get any movement out of it.
This last photo shows I can still have full access to my bench. The bracket will also hold my drill press, and other bench mounted tools as needed.