The shop where I used to work decided to carry a lot of Christensen Arms firearms, and a huge number of them had problems. We got a bunch of .300 Win Mag bolt-actions, and one turned out to have a proprietary thread pitch that was way too short for the muzzle brake that was installed on the rifle. All the other ones had normal proper - length 5/8x24 threads. Our only guess was that they screwed up the threading of that specific barrel and so they just decided to jerry-rig it. But that meant no other muzzle device or suppressor would ever fit on that barrel, not without a custom-made adaptor. And the threads were so short that a suppressor probably wouldn't have stayed mounted for long, even with an adaptor.
We also got in a bunch of AR-15s and AR-10-type rifles. Almost every single one had problems, ranging from bad fit-and-finish to crooked handguards and buffer tubes that had threads that were too short.
And the worst was their 1911s. We got in a few of those too, and the build quality was worse than most $700 1911s you can buy. Customers who knew 1911s would laugh when they handled it and then saw the $3000+ price tag.
I'm not sure what's up with Christensen, but I've heard similar stories from people who work at other stores. My guess is that they were fine when they just made carbon fiber barrels, but when they decided to make ARs and 1911s I'm guessing that's what caused their quality to take a dive. And maybe they've somehow gotten better since then, but they left enough of a lasting impression on me and my coworkers that I can never recommend them. I've never seen a company that used such high-end materials and managed to pass themselves off as being on the level of a company like Wilson Combat, but had such low-end quality and workmanship.