Yeah, good points. I'm a lib lab, but I'm pro-gun.
A couple of caveats.
One, I haven't heard a good reason why large magazines shouldn't be banned. A 30 round clip on a semi-auto gun, in the right hands, is not greatly weaker than the same gun full-auto.
Second,
really big sniper rifles. Semi-automatic rifles in hunting or anti-personnel calibers are reasonable. Guns that can fire armor-piercing ammunition accurately at ranges greater than a kilometer and that can easily disable airplanes are not. Guns like these are not needed to hunt any animal in north america. They might prove valuable for hunting Elephants, but there are specialized guns for those purposes.
I don't think the slippery slope you propose here works. Banning the big Barret sniper rifles won't be the beginning of the end for the .30-06.