It doesn’t seem worth getting into a pissing contest with someone over the Internet by attempting to discount their claim. The truth is that some rifles “like” certain ammo and maybe this rifle is one that works with it.
I make this statement from the perspective of my M1A. Back when I bought it, many people were claiming that the South African surplus was a solid 2 MOA and under performer. My M1A never managed better than about 6 – 8 MOA on SA surp. Did those other M1A owners lie? Probably not. After I switched over to shooting Malaysian surplus, I was shooting 3 – 4 MOA with no other changes. The people whose guns liked the SA ammo thought it odd that my rifle shot so much better with Malaysian surp.
After I started reloading for my M1A, I was able to shoot 2 – 3 MOA consistently and I expect to stay under 2 MOA once I put a scope on the rifle.
In summary, I have no doubt that some people stretch the truth about their shooting and the results they get. Most are probably like me and don’t – because that would defeat the whole point and validity of discussing these issues on forums. I’m a decent shot, but I have no illusions that I’m some uber-sniper or anything like that. It would seem silly to me to try and lie to people that I’ve never (and probably won’t) ever meet.