Howie,
1.5" groups at 60 yards with open sights isn't all that bad. I remember shooting my .375 H&H with open sights and I was similarly getting 1 to 1.5" groups at 50 yards. I don't think that it was me as it was the difficulty of aligning the factory sights.
I did get a scope though, and would you believe that, with about $750 worth of custom work, it now shoots better than 1/2" groups at 100 yards@!! :eek:
Are you planning on mounting a scope to your 45-70? I have an Elite 3200 1.5x-4.5x-32mm and it's great!
Zachary