Is "で一発だ an expression?


> こりゃたまげた! あっという間に見つけちまうんだね

I'm shocked. You found the food in an instant

And his reply

> ああ? 食い物なんて匂いで一発だ

From context I can gather it seems to be akin to ... I found it asap because
of the smell but I'm not sure how the sentence is being constructed

"When it comes to food, with the smell..."




The sentence structure is rather simple though it does not admit simple
translation into English because 一発 wouldn't correspond to a simple English
word.

The sentence is

  * 食い物は匂いで一発だ

with なんて adding 'such things as foods'. So literally:

  * Foods are 一発 by the smell.

[一発](https://dictionary.goo.ne.jp/word/en/%E4%B8%80%E7%99%BA/#je-3963) means
literally 'one shot' or 'one trial'. (一瞬 has the similar usage: この宿題は一瞬だ would
mean '(doing) this homework is one instant')

Here you can think _(detecting) food is a matter of single trial by the smell_
(if preserving the structure as much as possible).

