Nice, I write from Italy, I shoot in the national competitions for military rifle until 1955 at 100 meters and 300 meters, the target for 100 meters is the same of your.
I shoot sniper and iron sight at 100 meters and sniper at 300 meters, I am a good shooter whit iron sights,usually in the best ten, I want to say that is normal to put 13 or 14 shoots of the 15
that we shoot in the ten for the winner, 11 or 12 for me.Record is 15 in the ten and 10 mouches.
Precision of old rifles is exeptional whit the right reloading, I use a Springfield Kragicon 1898,but most of the competitors use Gustav M96 or similar, very good also Finnishicon rifles.
In the sniper competitions Carl Gustav 91B and Schmit Rubin K31icon/55 are the most used, but I use a finnish M39 whit PEM scope,and I am the Italianicon champion for this year.
In sniper 100 meters 15 ten on 15 shoot are absolutely normal, the difference are the mouches,whit 12/13 mouches is possible to win(last time I was second whit 12 mouches damn.)
I think that competitions whith old rifles are wonderfull, are the way to know and appreciate your rifles ( I have 39 old rifles and love it all).
Good luk,and enjoy you rifles !
romolo1956
PS you can see rules and report of italian ex ordinance championship on U.I.T.S. - Unione Italiana di Tiro a Segno (unione italiana tiro a segno)