Definitely worth calling them, but my understanding is that no one does a 1/2-28 thread suppressor for .30. At least not that I have seen. I read an explanation of it once, but can’t remember it well enough to even paraphrase why they won’t. I am in the same situation as you. My Tikka is threaded 1/2-28 and I would want a direct thread suppressor and not have to use an adapter/brake. I want to get the weight and number of components down.
I've used my SilencerCo Omega 300 direct threaded on a 1/2-28 threaded 300 PRC with no issue. I have Titanium base caps from Energetic Armament that I swap back and forth on it in both 1/2-28 and 5/8-24 depending on use. It's lighter than the original SilencerCo cap.
https://energeticarms.com/direct-thread-adapters/
