Excellent Gas Black
I changed my 3 gun competition rifles over to these gas blocks about a year ago. I love them. I now have them on 4 rifles. The fit and finish is exceptional. The inner diameter of the block and gas tube port is very consistent, keeping any leakage to a minimum. There is no leakage at the adjustment screw, and the adjustment is smooth and provides concise clicks (14 clicks to full open). Very easy to maintain, no little springs to break or loose. The internal port is .125", which is well above the typical gas port diameter of a rifle length gas system on a 16" barrel (.105"). No gas restriction at all. They are a bit pricey, but for me they are well worth the price.