Off of a rest at 100 yds I managed sub MOA with WWC 81 while breaking in a '55 Faz fresh out of the wrapper.
I've been close but never quite that good since. No more WCC '81 left. (And my eyes certainly aren't getting any younger!)
Using a quality ammo in a weight your rifle likes, you could do 1.5 to 2.5 if you do your part and the rifle isn't worn out.
I have one mk1 iii* thats been converted to a range rifle that can shoot under 2" groups at 100m and I'm shore that that rifle shoots better than i can. A mk4 depends on the head space and the quality of the barrel 3" to 4" at 100 yards is about what iv seen, some less some more.
I've found that bore condition and ammo quality are the two most important factors. Since the mk2's are generally less used they probably shoot a little better (plus the other trigger improvements and better quality control). Bedding also plays a part.
Mine's an MOA shooter easily with my handloads and a PH4C backsight.
Mauserlover, Some Mk.2s have extremely tight bores and require up to 500 rounds to break in. These rifles seem to be primarily 1955 manufacture and may initially print as poorly as 18" at 100 yds (mine). If you have one like this, be patient.