Installing gas blocks.... [Archive]

Hmac

28 July 2010, 20:46

I need to be educated about gas blocks. I'm building an AR15 SBR with BCM 11.5 inch barrel. My plan is for a 9 inch DD Lite rail so I need to install a low profile gas block.

My confusion revolves around set screw vs pinned vs clamp-on ( or any combination thereof). Is pinning the gas block preferable? Mandatory? The BCM barrel has one dimple, do I need to have Addco or somebody add the second dimple then pin the gas block? I've heard horror stories about people trying to unpin Noveske gas blocks to install their barrels - is this a universal experience with all manufacturers?

And, in what order do these installations occur? I have to get the barrel nut on, so do I install the barrel and rail mount ring to the upper receiver first, then send the barrel/receiver to get the gas block pinned, then install the rail when I get it back?

Rudimentary, I'm sure. Thank you for your patience.

Paulo_Santos

29 July 2010, 06:26

I have sent several barrels to ADCO to get the gas block pinned. It is just added insurance. It is overkill for the most part, but I liked the added insurance.

Honestly, with the one dimple and because the gas block will be covered up by the rail, the chances of the gas block moving on you are practically nill.

If you do decide to get it pinned and get a second dimple, it is pretty easy to remove the pin and the screws.

Hmac

29 July 2010, 07:38

So, after it comes back from Adco, just drive the gas block pin out, unscrew the two set screws, slide the GB off, barrel nut and rail mounting ring back on then re-pin/re-screw the gas block.

Do I understand correctly that the DD Lite Rail will slide over a low profile gas block? Some older posts on the subject suggest that that wasn't possible with the older version of that rail.

Paulo_Santos

29 July 2010, 12:09

So, after it comes back from Adco, just drive the gas block pin out, unscrew the two set screws, slide the GB off, barrel nut and rail mounting ring back on then re-pin/re-screw the gas block.

Do I understand correctly that the DD Lite Rail will slide over a low profile gas block? Some older posts on the subject suggest that that wasn't possible with the older version of that rail.

That is correct. It is real easy to remove the gas block and I was able to slide the DD Lite Rail on on off without removing the gas block.

Hmac

29 July 2010, 14:04

Thank you very much for the help.