Aero precision ar15 low profile gas block - Aero Precision AR15 Low Profile Gas Block

These gas blocks should work well. I like the nitride finish, and they should last a very long time, if not forever for most. I'm not sure they would ever go bad unless under maybe extreme use and heat, then a rapid cool or something. but things happen no matter the brand. My only complaint is the weird set screw spacing they use. Its only a minor ding, as some of us like to dimple, and use a dimple jig. Their odd spacing is not a option on the tools I've seen on market, like KAK and SLR dimple tools which do .400" .425" .450" .470" and .500" spacings. The AERO is .485 I think it was. You can still dimple, but would only be one set screw directly under the gas block, which still would be ok, but not as great as 2 dimples for the extra ease of mind. You could could have a special dimple tool made probably, then that would take care of that. So before you throw and gas blocks in the cart, you might want to inquire the set screw spacing, if you dimple your barrels.