I haven' t used a 30/30 in many years,haven' t even got one any more,have had a Marlin336,win 94 and a glendfield,and have taken a lot of deer with them and groundhogs on ocassion but used a 22 and 410 on most groundhogs because we ate them.
I hunted in the good old days when 6out of 10 hunters carried a 30/30,3out of 10 carried a single barrel shotgun,1 out of 10 carried a used military rifle.I have helped some track deer they shot even at shot range mostly because they couldn' t hit a bull in the a-- at 25 yds.But the ones that could shoot,they had no problems with the 30/30 and I have seen some including myself make unbelievable shots on groundhogs and deer.If the young fellow says he made those shots I will take his word for it.
What makes me wonder is how long some of the ones that knock the 30/30 so bad have used a 30/30.
And the cheap price of them now,I bought the glenfield for $79 don' t remember what year.but the used ones I have seen for sale they want an arm and leg for.
All in all I don' t think you have a problem with a 30/30 if you learn to shoot it ,if thats what you want to use.Myself have graduated to flater shooting rifles but won' t knock another guys choice.