The best gas block for low profile tight adjustment with a jam screw. - ODIN Works Tunable Low Profile Gas Block

This one fits on the .750 and the barrel behind it, is nearly the same thickness so, the drop off is almost not there. Fits like a glove, close and tight - has 2 very tough harden grade Allen heads , the shelf for these are finer threads to allow a very tight fit - Metal seems really strong. Adjustment is a jam style so, you can adjust till the system works, when you place the second seal on, no need to turn that extra 1/4 turn, there will be enough gas getting by one, not the second - Really tight seal.