Presumably “Main Character”
And I’d at least look at the social security website for names.
As I noted in post #2, and for which the OP thanked me for linking. Great minds think alike. 
Sorry. I did read the thread, but must have read over it.
As do the both of you. 
Grushenka?
Stinking Lizaveta?
See, I’m getting a two name vibe with this one.
Maybe a Betty Anne, or a Sue Ellen. Or even Barbara Jo.
But that’s just me.
Grushenka? “My little pear”? 
My name is Sally. I always thought it was a name for some poor depression-era woman living on a sunflower farm, lol. Baking bread, feeding chickens, staring out over the vast plains, watching for Eb the mailman to drive up with her magazines and catalogs… Sally. Named after her great-grandmother.
She sounds like a Maggie to me. Mag for short, or Magpie to her friends, if she had any.
Last name starting with M, for alliteration. Maggie McCullum, maybe?
Wichita, KS? Is “Dorothy Campbell” too on the nose?
How about ”Dorothy Gale”? 
If you’re interested in something a little odd, you could try Jerusha. It’s a biblical name that was somewhat popular in the late 1800s and then had a bit of a resurgence in the seventies and early eighties. It’s said to mean inheritance.
Victoria Emerald Shakely
I would vote against too much alliteration though, lest you fall into the “Superman’s LL” trap.
Do a favor to your readers, and make all the names of main characters sound and look different.
Absolutely this. I write role-playing game adventures, and I always strive to do this. I still haven’t forgiven Professor Tolkien for giving the two big-bads in The Lord of the Rings similar names. 
On the other hand, all the first names should not be unique to them. I know several Mikes and Michaels, and most would find it unusual to know a bunch of people that all had different first names.
I advise writers to use https://www.behindthename.com, especially the Random Renamer tool and the Meanings tool (found under Tools). The site is a deep dive into etymology.
Try also https://surnames.behindthename.com for surnames and https://places.behindthename.com/ for placenames.
Are you saying to use some common names, or are you suggesting there ought to be multiple people with the same first name?
If the former, i agree. If the latter, please, no. This is fiction. The gun means something, and the names should all be different. At least, if you want me to have any chance of keeping the characters apart.
