Mr Buffett once commented that with (now) 392,000 employees, it's pretty much a certainty that at least a few of them are behaving badly at any given time, despite management's best efforts.

In the same vein, since Berskhire owns hundreds of companies with thousands of operating units, it's a near certainty that some of them will be in business lines that aren't very palatable in the eyes of an investor. (perhaps justifiably, perhaps not, probably some of each). I definitely don't love the idea, to say the least, but as the saying goes, everybody is complicit in something. All you can do is minimize it.

Ironically, the wealthier you are the more unavoidable such things are. Anybody owning an index fund is complicit in a LOT of things. Probably more, on a percentage basis, than an owner of Berkshire alone.

So *why* do we own this?
Looking at it purely as a financial decision, it's a slam dunk that Berkshire would have been invested in tobacco firms these last few decades, but they haven't been, presumably because management didn't feel comfortable with it. I rather doubt Mr Buffett would have bought a gun parts maker as such, but it's a small part of a bigger division (Marmon) and I presume the decision in this case is left to division management. I've been in the exact situation myself: owning a company that wouldn't do business with a certain class of firm, but delegated some decisions to someone who took the initiative in the other direction. We lived with it, and it wasn't illegal.

Jim