When I owned Edison Price binding posts, I had the same issue. Threads are not worn out, the split barrel has become compressed over time by the nut.
Don't laugh, but you can cut a very short piece of wooden dowel rod and press into the center (between the split halves) and return it to it's original shape. Leave the wood in full time, it helps dampen the posts as well as stopping further compression.
The only caution, select the right diameter dowel rod so you don't crack and break the Edison price binding posts. I've also had great results putting Caig Pro Gold on the dowel rod and connector. Everything stays clean, conductive and free from corrosion.
Let us know if successful for you.
Don't laugh, but you can cut a very short piece of wooden dowel rod and press into the center (between the split halves) and return it to it's original shape. Leave the wood in full time, it helps dampen the posts as well as stopping further compression.
The only caution, select the right diameter dowel rod so you don't crack and break the Edison price binding posts. I've also had great results putting Caig Pro Gold on the dowel rod and connector. Everything stays clean, conductive and free from corrosion.
Let us know if successful for you.