The bolt on my AR 10 build isn’t going back far enough to pick up a round. Aero upper and lower, Wilson Combat BCG and barrel, geissele carbine buffer tube spring and buffer. I have switched buffer springs with a BCM out of another rifle and even another buffer. Still only goes back to a certain point and stops. I did try a different lower that had a rifle length fixed stock on it and it worked fine. Everything I have searched says a carbine buffer tube will work. What am I missing?