I think your probably right bushido, more ground than not ground ,common 7th are plentiful and usually seem to be ground. of course if you go by high end collecotrs groupoings it wouldnt seem so, because most of those guys carefully collect Mummed examples. I know a couple guys that if you used their outstanding collections you'd think all japanese rifles were mummed ,matching and had all their accessories simply because every gun they own does..but looking at all the ones Ive owned and saw , for sale in person or online,I agree the majority are ground...same is true of series 40's.
Hello davef :
If you look at major collections you are indeed going to see pristine examples, in part it is due to the fact that these rifles were available in that condition back in the 'good ole days'. As the decades have passed you will find less of such quality samples, some fellows imply that we are seeing the bottom of the proverbial barrel, and that in 4 to 5 years Japanese arms will dry up.
I know serious collectors who only want mum-match-mint examples, in years past there were choices depending on the thickness of your wallet. Also rifles moved much more slowly from Vet to show and the outlets were few, today with the many internet sites and world wide expossure the competition is fiercer for what is surfacing up.