If guns stop rape, then why does the US have the 7th highest rate of rape per 100,000 population in the UN, as of 2012? Behind Sweden, Jamaica, Bolivia, Costa Rica, New Zealand and Belgium?
Because the majority of those are in situations where someone doesn't have the know how, tools, or ability to fight back, or because they've been drugged or alcoholed up.
That and it's not like you expect it to happen so you're already fully prepared. A rapist doesn't give you 24 hours notice, with a time, location, setting and other basic information. Therefore, even with a firearm, being caught off guard means you may not have time to use it anyway.
In fact, your entire statement is flawed off the idea that the existence guns is supposed to negate the existence of rape, but at the end of the day it ignores far more than a few variables per situation.
Clearly not, but even in that statement it's still a flawed black and white, because there are most assuredly cases where firearms have been used to stop rape, just like there are cases where it gets taken away and it doesn't help.
But what you're doing is slightly shifting the focus from 'Can a firearm be used, and have firearms been used, to avert rape?' (Which is a yes) into a 'What's the highest rate of rape per country? So clearly your method doesn't work.'
That secondary question is flawed to the arse ends of the universe though and is easily interchangeable to the point that it negates use as an argument.
Clearly big dogs don't help, your country has-
Clearly locks don't help-
Clearly polis don't-
Clearly private homes-
Clearly- well, you get the point.
A firearm is a tool. It's the user that is the one that causes any problems with it.