For what it's worth, I own guns and personally I've made a decision not to keep them at home while my kids are small.
When I was 3 or 4, I was playing with my older sibs, and one of them jokingly said something about a gun...I went inside and came marching out with one of my dad's shotguns. While it wasn't loaded, and my older brother grabbed it from me, the memory of having done something stupid like that proves to me that having guns in my home, with little kids, isn't the right thing to do.