Hi I have a question about my after market quad rail. I went to put it on my AR10 and it sits a little off to the right the instructions say I have to adjust the barrel nut until it is aligned is this common with after market rails and is it ok to adjust the barrel nut by tightening or loosening the nut to align. thanks.

Your indexing is off from the factory and if it is off kilter, it means one of two things. The factory did not torque it tight enough and came short of proper alignment and/or they ran up to the maximum torque one can apply to the barrel nut and were simply too lazy to either use shims or loosen and start over.

Either way this sounds like a quality control issue and my MP Sport 2 is also slightly off. Since I mount my vortex strike eagle on the reciever guess it does not matter but the iron sights could be slightly off.