[Hayzer912]

Hello everyone! I am currently building my first custom AR15. I purchased a Ruger 5.56 NATO barrel from a guy in one of the AR Groups I belong to and it has what look like pin holes where the gas block mounts. The holes are on the top of the barrel near the exhaust "hole". I am assuming this means the block I choose must be fixed to the barrel using those pin holes. Since I am unfamiliar with this type of gas block mounting I wanted to ask if anyone knows where i can get a gas block that will fit this barrel? In all my searches I am only locating gas blocks that mount with the set screws. HELP!

 

[44blkhwk]

At first glance I would say the holes are for installation of a Front Sight Base(FSB) but the location is wrong as those holes should be on the bottom of the barrel not the top.
I have only built a couple of AR's but I have yet to see a gas block that would be pinned like that.

 

[Hayzer912]

from what I am finding the barrel belongs to a Ruger 8500.......which pins the block to the upper portion versus the bottom.

 

[44blkhwk]

Well there you go. First one of those I have seen. I wouldn't think it would interfere with a gas block installation that uses set screws.

 

[Tacky]

Ruger does their taper pins on the top of the barrel for their front sight block. Everybody else does them on the bottom. So to use them you will need a ruger front sight block.

You can do a bottom set screw or clamp on gas block as well, fairly simple done tons of them. If you have questions just ask, know the ar platform well.

 

[kwg020]

Ruger mounts the front sight base with pins at the TOP of the barrel and not the bottom as does everyone else. If you want just a gas block I would suggest you taper pin in the holes and file them smooth with the barrel. If you want a Ruger Front sight and are hoping that the pins will line up, good luck.

kwg

 

[tunnug]

No need to use the pins unless you're doing a rebuild to make it original, if you have something else in mind the only thing that matters is that the gas block fit the barrel, set screws will work just fine, that's how mine is put together and it works great.