Interestingly, this thread took off more than I had realized.
I am never rude to TSA or Customs. I don't think any of the vandalism has happened by people that I've interacted with. Having said that, IAD is my least favorite airport to go through when returning to the US. I find the Customs people rude.
To clarify, no plastic ammo box is that hard to breach. I chose to use TSA locks that accept TSA keys to keep them from cutting the locks and snipping the hasp as well. Snipping the hasp and rendering the box useless for further trips is the vindictive and malicious part of this.
I remove the bolt from my rifle and place it in a slot cut into the foam. I then use a cable lock on the rifle.
You are not present at LAS when they inspect your rifle. They have never asked to open my handgun case. I've been present for it to be opened pretty much everywhere else.
I do not use TSA locks on my rifle case. I bought some, but had questions about their durability.
In the past, I have worried about my ammo being taken from my suitcase and misplaced. On my trip with Western Safaris in May, I took my .338-06. It was a leap of faith for me. The ammo arrived safely.
My ammo box was unmolested/undamaged upon my return to Vegas after the hunt. The only odd thing that happened was that a clean long-sleeved light green Columbia shirt was taken out of my suitcase. If anybody came home with one, let me know.
In the end, I suspect that there is a lack of accountability for needless destruction or tolerance of TSA arbitrarily "teaching people a lesson".
I will continue to bring my own rifles on safari. I like them too much to leave them behind.