I just went through this with my .308 Win, I did a BUNCH of Video Watching on this, i seen the video you linked as well. I bought a Can of Shoe Polish, JB Weld, EVERYTHING i needed to Bed the Rail when it Got here. When my Nightforce Rail arrived it ended up Fitting my Rem 700 SA Reciever like a FINE TAILORED Suit, I Got DARN LUCKY! From all of the research i did, they Claim over 95% of Rem 700 Receivers will be Off, Some FAR worse than others, i seen some that were BAD! Then their will be the RARE Exception that you run across a Square Reciever, or VERY Close. Mine was SO Close that there was no need to Mess with it, I could not get a piece of paper under the Rear of the Rail with the front Screws in, Not even my ULTRA Thin Onion Skin