Switched to FF tube, POI changed?

[45Badger]

I installed a YHM ff quadrail on my RRA Entry Tactical. All went surprisingly easy and well. Also replaced FH with a YHM. When I took it to the range, it shot almost 2" right at 50 yards:(

I adjust rear sight to left (almost all the way) to correct this but I think/hope there's another issue or correction available. Any chance that I got the front sight canted to the left? How would I recognize this? What else would cause such a dramatic shift in impact? Thanks for any and all insight/advice!

[kwelz]

You had to remove the barrel nut to install the FF tube. This can cause your POI to shift. Honestly I am not sure how much the FH will have an effect on it but it seems like it would to me.

[rob_s]

If you had a standard FSB that is installed with two pins and you installed them correctly then it's very hard to cant the FSB.

Did you properly torque the new barrel nut?

Sometimes things just shift between removing and reinstalling the barrel. A 4 MOA shift seems excessive, but if you have the pins in and torqued the nut then it is what it is.