No, you are ok, but I'd lay in extra shells. I have 10 boxes of 12 ga shells here and three more in the back of my Bronco.
Don't you have a handgun? You should.
I have a Glock 17 with six 17 round mags, plus a Kimber Gold Match 45 auto with several Wilson Combat 7 round magazines.
I have a kimber 40