First boss fight with Carnby

[NOCTURNE]

Hi

Now that everybody is listening, I have a question, maybe someone can help me out.
Although I completed the game 10-20 times I still not understand entirely. :) Sometimes when I try to kill this boss I lose all my ammo and that monster just won't die. Sometimes I do the same thing and it dies from only a few shots...
So, I shot him, after that he start collect power, and now I shot him again. After this hit he fly away and after a few seconds he come back. I did this trick until he dies or I run out of my ammo. And this is my problem, sometimes it works, sometimes not. I missing something?

[PL4TiUN]

i have play this game long ago on Playstation i remember wasted all my ammo on that flying mob too XD but after that i realize with a few shots of the grenade launcher u can beat it.

[𝓓𝒆𝓿𝓲𝓧]

awesome game i played this game when i was 7 years old

[Vo1oD]

I fixed this bug by trying previos save before first entering the library. And my monster died when I was not actually shooting it. That's a bit strange.