Bi-pods are typically mounted on the forearm or hand guard rather than attached to the barrel of a rifle. Attaching items to the barrel changes barrel harmonics and so changes POI. Apply pressure to the barrel also changes POI.
Of course, you can do what you want....it's your AR. Just sayin'....
With a low profile gas block, you can use the longer free-floating rail to mount both of your items. You'll find some threads regarding these rails in this forum for sure. Sorry...don't have a specific reference to point you to...my free-floating rail does not extend past the gas block.
Bipod mount
Linear Mode
