Thats a great velocity for the 173 grain load! And fantastic accuracy.
I took my .270 (the same as yours) and finally put a scope on it and shot it with a couple of reloads. I ahev already shot it a bit with open sights and got two inch groups with it, and shot a good fallow buck with it last month - the very first time I took it hunting too. You have to be happy when you get a rifle that already knows how to hunt.
So I put a scope on it and sighted it in and then got exactly one inch groups for everytihng at 100 yards.
what am I suppossed to do now? it was going to be a donor rifle for a 7x57. I am embarrassed to tell you how cheaply I bought it although there is not a thing wrong with it. Oh well, I just suppose I will have to find another 7x57mm somewhere.
I think the scope is going to come off again though, the Brno fits me so well for open sights.