Yes! you do need the standard barrel nut! Be sure to re-torque the barrel nut to a minimum of 35 Ft Lbs when installing it.
In all honesty your YHM Quadrail is much more sturdier! Only a thought!
The Constitution is not an instrument for the Government to restrain the people. It is an instrument for the people to restrain the Government!
“Americans have the right and advantage of being armed. Unlike the people of other countries, whose leaders are afraid to trust them with arms.”
James Madison. Author of the 2nd Amendment