The only one i don't think is such a hot idea, is the smoke-stack poster. People tend to roll their eyes these days when anyone invokes nazism for political purposes.
Perhaps people who are already solidly on the "pro-gun" team might react well to that, but i certainly don't think it would attract much attention from anyone on the fence, and certainly wouldn't get a second look from anyone on the other side.
Frankly, in terms of people on the other side - it will simply provoke a knee-jerk reaction that deteriorates the level of discourse - and i don't think any of us want that.