I am pretty sure that I have posted this link before, to a very interesting article about how much spare ammo is enough to carry. I came across it again today, after seeing a comment in a gun forum thread about carrying extra ammo in which someone replied they do not carry a spare magazine for his/her semi-auto pistol.
So, I figured it might be a good idea to post it again because not carrying at least two spare magazines is
begging for trouble as far as I see it. Some truly eye opening details
about a police officer's involvement in an armed encounter with a really
bad guy can be seen in the article at the below link.
All the best,Glenn B