The ammo may be the limiting factor.
I don't like 5 shot strings for accuracy. It is better than 3 shot strings but not as good as 10 shot strings. And even 10 shot strings are not always definitive.
I once did an ammo test of two different lots of .22 ammo. 3 ten round groups of each lot. Lot "A" had the best group, Lot "B" had the 2nd, 3rd, and 4th best groups with Lot "A" bringing up the rear with 5th and 6th sized groups. I needed over 800 rounds to take to the National matches. Which lot would you choose?
Trying to compare single examples of different factories guns doesn't prove a whole lot either. You can get a clanger from anybody, you can also sometimes get a gun that defies expectations (to the good) or for some reason decides it "likes" a particular manufacturing lot of ammo. I shot for a team that in the days before I shot for it had five accurized M1 rifles and they discovered that a particular "lot" of WIN 1952 Armour piercing ammo would shoot under 2 minutes of angle in all 5 guns. AP ammo wasn't supposed to do that. And older or newer AP ammo wouldn't do it either. One of the team members had access to the underground test tunnel at WInchester.