So am I to understand that if you agree on everything except guns then it is a bad match?
I think it depends on how important guns and RKBA are to you and how strongly anti the other person is.
I imagine that if on some other board a guy posted "my wife hates football so much she says its either her or the superbowl" that a lot of people would advise him to run. Again, its not about guns or football, its about being with someone who has such little respect for you that they will foist ultimatiums on you (of course one must recognize that forcing an anti to live in a house with guns is just as much an ultimatum as forcing a gun nut to live in a house without them).
The original poster appears to me to have had the woman longer than the interest in guns, so that is a little different than someone who's been active in shooting for a long time before the relationship being told to give up the guns or the woman.
Also, many antis begin their trek to "former anti" status by "allowing" their SO to keep guns in the house ... so unless this woman is a member of the VPC or Sarah Brady's niece or something I seriously doubt that she's so staunch in her position that she'll give up on the relationship just because of the gun issue (and if she does, well then you where probably better off anyway).
I don't think that anyone in a healthy relationship should be laying down ultimatums (with the possible exception of
"you sleep with someone else and we're through") This goes for both sides.
If she is indeed a hard core anti then you have a tough decision to make ... I would figure that if my wife gave me any ultimatum before we were married (back when we were being "polite") I would assume that means that if I backed down that she would expect to ALWAYS get her way ... and "...till death us do part" is a long freaking time to never get your way.
I would sit her down and talk to her about this. I would ask her if
she thinks this is an issue worth ending things over. You might be surprised, she might have a knee jerk reaction and upon further reflection decide that its not that bad afterall.
Here's some places you can get information about women and guns.
http://www.womenandguns.com/
http://www.2asisters.org/
http://www.paxtonquigley.com/
And if she's afraid your interest in firearms is going to turn you into a hard core right winger or something, send her here
http://www.pinkpistols.org/
http://www.liberalswithguns.com/
and of course
http://www.a-human-right.com/