The original sounds of [g] in English and the sound of ‘ㄱ’ in Korean by HMJ phonetics are as follows.
그 ——-> three ultimate particles of sounds, that is, [( )], [ㄱ] and [ㅡ]
The sound of ‘ㄱ’ in Korean
[ㄱ] ——> one ultimate particle of sounds
Therefore, [g] ≠ the sound of ‘ㄱ’ in Korean.