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Just make sure you get a clamp on as opposed to a set screw. The set screw ones will come loose eventually.
If you want an adjustable one, get the clamp on click detent from Seekins
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Their are multiple ways to ensure a set screw gas block does not come loose.
First off, many of them use screws with small teeth that cut into the barrel and help prevent the screws from backing out.
A common method to prevent the screws from backing out is Rockset. Many people get by with red loctite, but rockset is more heat resistant.
Another less common method that works is staking the screws in place. Similar to the method gas keys are staked the metal of the gas block can be deformed to prevent the screws from backing out.
I always reccomend dimpling the barrel to ensure the gas block doesn't rotate.
Some guys like to go all out and pin the gas block, obviously it works very well.
I have one caveat for cheap gas blocks, I would avoid any of the low profile Aluminum gas blocks as they have more trouble with heat and sometimes the gas port burns a hole through the side of them, leaving you with a bolt action.