I think people perhaps overestimate the effect of a father's shotgun on a young man's plans to date his daughter. My father has owned a shotgun (not to mention several rifles, plus other stuff) since before I hit puberty. Its certainly true that I didn't date until I went away to college. On the other hand, I think my non-dating before college has much more to do with my general nerdlyness and the lack of male nerds of sufficient qualilty in my high school. My sister is a pretty good example of how having a shotgun-owning father does not prevent young women from dating. Margaret is almost four years younger than I am, and she started dating before I did. I'd also say that some of her boyfriends were of dubious quality. My parents certainly worried more about her choice of boyfriends than they did about mine.
There is a difference between Margaret and me that does have something to do with guns, though. I learned to shoot and she didn't. I was much more interested in weapons than she was, and Dad ended up taking me to the rifle range when I was in junior high and high school. By then I already had plenty of nerdly frustration to work out by blowing holes in paper targets, and it was a good bonding experience with my Dad. It was also really cool that my Dad was the only guy at the rifle range who brought his daughter along, though there were a fair number of guys there with their sons. I don't know if this has had any impact on the men in my life, but I suppose at the very least my parents know that if I were to ever end up with an abusive man in my life I could purchase a gun and blow his brains out.
So, my friends with little baby girls, forget those plans you have of cleaning a shotgun when you little girl brings over her first boyfriend. For true peace of mind you want to buy her a .22 caliber rifle and start taking her to the range when she's twelve. (Don't forget the gun safety lessons.)