It would be interesting to see if you're right. I've always put my range limit on the 30-30 to 150 yards. A 300 yard shot with a 30-30 is Quigley Down Under stuff to me.
Lemme guess... Model 94 with buckhorn sights, right?
The one I grew up with had a sight I've never seen on one before or since. It wasn't a flip up peep sight mounted on the tang behind the hammer, it was a peepsight mounted just in between the hammer and the ejector port. 2 screws on the side of the receiver and then it came over the top in front of the hammer. Simple as hell, durable as all hell, but doubled the sight radius on the thing.
First deer I ever shot was with that thing at ~250 yards.
Wiley.