I just picked up my CZ 455 Varmit, 16" with the thumbhole stock. I loved the gun immediatly, and can't wait to get glass on it and break it in. The owner of the store wanted to put a suppressor on the barrel to show me the fit, as I will be buying one after the first of the year. Low and behold, it is not 1/2 X 28 like I thought it would be, but 1/2 X 20, and maybe even a metric thread count. Can anyone advise me about this? Can I put an American made suppressor, or do I have to go with Parker Hale, or another company that was mentioned in the instructions? Does anyone make an adapter for 1/2 X 28 thread?