How to come up with a nickname?

Question

I need a nickname for an expert marksman, their name is Cpl Thomas Jenkins in the USMC.

Answer 1

pick two adjectives that describe the person and clip them together into one word.  Sharp, and surly = Shirley.  

Answer 2

Gunny?

Oh, okay. Nicknames by rank? Thanks for telling!

Answer 3

There are no expert marksman in the Marines, either they are Marksman, Sharpshooter, or Expert.  And calling him Gunny are for Gunnery Sergeants, not for Corporals.  "Their" name is Cpl T Jenkins?  How many Cpl Thomas Jenkins's are there?

Answer 4

You want to do a favor to Cpl Jenkins? Don't try to give him a nickname. He is going to feel like a douchebag, and if his friends find out about it, they will tease him without mercy. What you think is funny or cute could haunt the guy forever. I shot expert every year I was in the USMC and I was company high shooter in bootcamp. Nobody ever gave me a nickname about that. Some of the guys who had the same rank as me called me "Wrecker" because I was a big and it kind of sounds like my last name. I was a Sgt. when I got out, and that's what people called me.... Sergeant.