I've never named any of my guns or motorcycles, however 2 of my guns came to me with names already attached.
The first is a 5.5" Ruger Redhawk .44 Magnum. One day it found it's way into the gun shop at which I worked. It was in excellent shape, perhaps unfired...but it sat on the shelf for many months, even though the asking price was quite low. On the right side of the barrel, near the muzzle, the name "Lucille" was very professionally engraved in a nice cursive script. I guess that was what was keeping it from selling. At first, I didn't care for it either, but then it dawned on me that my Father had an older sister named Lucille, who had died when she was only about 9 years old or so, around 1930. When the shop owner dropped the price yet again, I snapped it up. I'm really glad that I did, because it's a very sweet shooter, and I think everyone who's ever shot it has expressed interest in buying it...even after I've pointed out the name.
The second gun I own which has a name is a SA M1A Bush rifle. I bought it from a great guy who had been a "fast-draw" expert back in the 60's ( at least, I think it was during the 60's.) After winning a fast-draw competition, he began working in TV and movies as a stunt man and sometimes on screen bad guy. When I was buying the M1A from him, he related to me that he was shooting it one day with a female friend (I forget her name, but he showed me one of her paintings, and said she was Jimmy Hendrix' girlfriend at one time) when he decided the rifle should have a name. He asked her what a good name would be, and she answered "Clementine". He liked it, and the rifle case that the M1A came in had the name scrawled on it.
So, I do refer to those guns by their names...but my other guns' only names are "Glock", "Smith", "HK", "Steyr", Walther", etc.
Tim