Aaron-Lagann
Banned
I now stop using the handgun as soon as I leave the mansion to go to the guardhouse for the first time. I don't like using the shotgun or any weapon for that matter immediately until I have some amount of spare ammo on the side (at least two ammo pick ups minimum). By the point I leave the mansion for the first time, I've already got like a couple dozen shotgun shells that I switch over then.
Once you get down what rooms you need to go through, you'll have more than enough ammo for all the zombies and you can't ditch the handgun pretty much immediately.
What's your best time?