I am in the process of building my first AR and i need to attach my Spikes low profile gas block. The instructions state that it is recommended to dimple the barrel so the set screws will have more bite. The barrel i have is: FN Cold Hammer Forged 16 Mid-Length Barrel (5.56)

Is there a jig available online that matches up with the location of the set screws on your gas block?

No there is not. You should first make alignment marks on the gas shoulder and gas block to ensure gas block alignment. Slide the block on, crank the set screws to hand tightness. Next you remove the rear set screw, take a 5/32 drill bit, and go through the set screw hole (do not destroy your threads). Dimple only deep enough to get positive bite for the set screw. Replace the set screw, using red loctite, and crank it down as firmly as you can by hand. Repeat this process for the forward set screw.

Be sure to maintain your gas block alignment during this procedure. Constantly check to ensure it is good as you are working. If you shift the block while dimpling, your gas system will not flow 100%.

After researching the procedure, the hardest parts sounds like keeping the gas ports in line while drilling the dimples.

Any suggestions on how to line them up before the allignment marks and how to keep it from moving?

thanks for the prompt response!

Bring a straight line back from the gas hole to over the gas shoulder. You can nearly eyeball it because it is so close. On the gas block, you do the same by bringing the line inside to the back and up the rear side. When you slide it on, watch the line on the barrel and keep it centered/aligned with your gas block mark.