Now while you have the lower hand guard snugly seated in your Rear site base with the lower hand guard retainer as pictured in the photo above MARK the front end of lower hand guard retainer on the barrel.
Use a sharp scriber. You dont want the scribed mark to be 1mm away from the true edge on the barrel.
In THIS case, distance between the edge of the HG retainer and locking lever (axis center) is 5.93 mm
I used different files and carved it out. Its better to stay towards the receiver than the muzzle.
If the locking pin does not want to close/lock/swing you will have to go deeper and/or towards the muzzle.
If it turns out loose, well.. you went a bit too far towards the muzzle, now you will have to tac weld the divit toward the muzzle and start with a file again. Bear in mind we are talking in fractions of 1mm here..
Now if we had a mill, we will be using a 15/64 ~.22" end mill and go about .11" into the barrel..
Here I have managed to achieve a very tight and snug fit. A good fit means that the locking lever will freely swing while making a constant contact. The retainer itself (when locked in place) will have minimum PLAY, specifically to the left or right!
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Last edited by fredieusa; 07-04-2009 at 11:01 AM..