theft deterrent

You should post in Fifth-wheels.

Lock your hitch on it. Then you can use the bed of your truck also.

12 Guage with OO Buck.

There are a number of different king pin locks available. Here is one.
I use this one.

Grumpy374 wrote:
12 Guage with OO Buck.

A man after my own heart.

But, I prefer #4 shot. Less penetration through sidewalls, but will still get the job done at close range.

On a side note: One time I was talking to the Loss Prevention officer of my company after another of our stores got robbed. He asked what would make me feel safer in my store. My response: "12 gauge pump loaded with #4 shot." He did not respond to me in any way.

Moved from class C.

You could block it & take the wheels off. You could block it enough to take most of the weight off the wheels making it difficult to steal & the next trailer down the line an easier hit.

Replacement value insurance and a kingpin lock.

Daryll

A short length of log chain and padlock. Nothing fancy. Wrap the chain once around the pin and padlock it as close as possible so it won't slide off.
Nothing will prevent a theft given a determined thief who has enough time and tools. The chain/padlock is simple to use and easy to remove when you're ready to hook back up. The best you can do is make the theft prevention enough that the thief will go somewhere else easier.