No they are not. A gun is no more inherently a weapon than any other inanimate object. More guns are sold to and used by civilians for sporting reasons everyday than have ever been used by civialians for offensive or defensive reasons. That's not just in the last year, or the last decade, or the last century. It's since the inception of the gun itself.
Actually...the inception of firearm(see fire lance and it's immediate off shoots/subsequent developments) was for warfare and since then their primary and widespread uses has been warfare(see handgonne and arquebus). In fact just the opposite could be argued. Only in the relatively recent history of firearms have they been primarily personally owned items for the common person and not weapons of war issued to troops or owned as a requirement for use in a militia (see brown bess). These examples while not the end all be all, are a pretty good outline of firearms usage and ownership from inception(~700AD) to transition into common private ownership(~1700)
Also you're arbitrarily restricting the definition of a weapon as something used against another person. On top of which you're making a false comparison. Qualifying all guns sold for sporting purposes against all guns USED (Not just sold) for offensive/defensive purposes. Do you have stats to support that conclusion or is it just speculation?