Just some additional anecdotal evidence: I have a custom-built M14 that has a chrome-lined Krieger/Criterion barrel. Chamber is amazingly tight, headspaced at 1.631 (which is more bolt/chamber installation than barrel manufacture, but I digress).
I was shooting naked irons on this gun with Magtech 150gr FMJ retail ammo yesterday.
Shot a 5 shot group where 4 of the bullets were in the same hole... I had to really squint to make out each distinctive ring, I thought I had missed the target with 3 of the shots at first. Just astounded.
Of course the 5th shot ruined it all, but that was 100% me losing form from prone and sending it 2" to the right.
I really wish I had put that 5th shot in the same group... it'd be pretty cool to brag about having a 0.1MOA M14 rifle.
Probably all a fluke and I'll never reproduce the event again, but I have been extremely pleased with this barrel.