So i've decided to go with a Larue 12" rail, and a Larue low profile gas block just to save myself of the pain of having to take the rotary drill one again to my AR. Now it says on the Larue site that the GB (this one) mounts to the barrel using 2 set screws located at the bottom. Then they hit me with this "gun-smithing will be needed on barrels without divots."

English is not my first language so i may be missing the mark at the divot part but still, would like to know the install procedure for this particular GB and while we are at it, should i consider any other GB or are Larue gas blocks the standard when it comes to low profile mounting. I'll be honest, when it comes to gas blocks, today is the day im gonna do some learning.

By the way, the rifle in question is a BCM 16" standard middy. Just FYI

Thanks in advance!

J

The divots are also referred to as dimples .. small indentations for the small set screw heads of the GB to index into.  

... many of today's new barrels start life with at least one dimple/divot already in it directly opposite the gas hole in the barrel ... with a barrel of this type the mounting of that type of GB is really simple. You just slide the GB on ... insert the rear screw into to the dimple/divot that is already in the barrel then take a drill bit one size smaller than the screw hole .. center the bit in the hole and start and second dimple/divot ... then remove the GD get a bit the size of the screw and finish off the dimple/divot to match the others size and depth .. remount the GB drop some loctite on the screws and tighten.

If the barrel does not already have one dimple/divot in it then it becomes a little more difficult but still vary possible.

ETA Just be careful not to mess the threads of the GB up when drilling ... make sure to keep the bit completely perpendicular to the the GB.

good explination.

Or buy the jig.

http://www.bravocompanyusa.com/BRDE-Fixture-for-Dimpling-Barrels-p/brdejig1.htm