I just received a BCM 16" middy barrel along with a BCM gas block and tube. The barrel is already dimpled. After sliding the gas block on till it hit the shelf I tightened the set screws. As I tightened the screw that had the dimple (there was only one dimple) the block backed off of the shelf maybe 1/16 to 1/8. Is this going to be a problem or am I worrying about nothing? Thanks
By traditional design, there is a handguard cap that goes between the FSB or gas block and that ridge. You don’t have that handguard cap, so that leaves a small gap. There are a few companies that have designed their gas blocks to butt up against the ridge since nobody uses traditional handguards with low pro gas blocks, but I don’t believe BCM has gone in that direction, yet.
ETA: This is the Handguard cap that fills that gap… http://www.bravocompanyusa.com/Handguard-Cap-Round-750-AR15-p/handguard-cap-round-.750-ar15.htm
Worrying about nothing. That stand-off is to accommodate a handguard cap.
Thank you
The factory dimple is set directly opposite the gas port if done correctly. To confirm, take out the rear set screw and turn the block 180 degrees. Line the gas port up in the center of the screw hole and see if the block is in the same place relative to the shoulder on the barrel. Odds are it will be.
The dimple is there for a reason, so people don’t attempt to seat them to the rear like you did and then wonder why it’s malfunctioning. The stand off accounts for the placement of the handguard cap which is about .028 inches.
I wouldn’t say nobody…
I stand corrected, only MistWolf uses traditional handguards with LP gas blocks. 