Almost never fails - its the shooter not the gun
Yes, modern guns are CNC machined to shoot almost dead on.
If shooting it and its off. Its almost never the gun. Yes, its hard to believe but you do need to do the "make me believe test."
1) Do not adjust the factory sights.
2) Shoot from a bench rest to take as much of you out of the shooting equation. Gun on sandbags, Your arms on the bench, You sitting down. Basically, the only reason your holding the gun is to pull the trigger and prevent the gun from falling.
3) Have an experienced shooter try it out. Have several shooters try it out.
Yes, you have to have others make you believe its not the gun's fault. Its a very odd but common belief.... that if your not accurate its the guns fault. This is true of even seasoned shooters with a new gun.
I had this seasoned shooter (30+ years of shooting). Just got a new XD from the gun show that morning and he was about to "adjust" the factory sights. Of course, he didn't have a sight pusher so he proceeded to bang on the sights with a small hammer - just a mess. Fortunately, I couldn't let him do it. I did intervene and had him do the benchshoot. It was him. Luckily, he only ended up with a few nicks on the front slide (from where he missed with his hammer).
Hope you try it and become to believe it's not the gun -- it's you. 99.999% of the time this is true. Unless you've dropped it and the sights are all messed up or someone had previously adjusted the sights or replaced them with different ones.