There may be more guns, but there are less households since 1973 that own guns. This means that those who have guns tend to collect them. Me having 1 gun or 10 guns doesn’t make me any more or less likely to commit a crime with them. I’m not sure how this helps your case.
https://vpc.org/studies/ownership.pdf
Again, logic fails you. Yes, an AR or AK can do more harm than Pa’s squirrel gun, but the fact is we didn’t have the same number of shootings back then even with Pa’s squirrel gun. The amount of people killed is irrelevant to the fact that the crimes didn’t occur in the first place. But, just to entertain your faulty logic, a person could have walked into a crowded theatre with a 12-gauge loaded with 00 buck and extra shells and killed plenty of people if he/she so desired.