Fucking hell I haven't heard Metallica seriously in years, kinda grew out of 'em when I was 13 - 14 and discovered direct downloading, still though I revisited KeA to properly critique this tune. OKAY, let's start on the bad, your drums are dry as fuck bro, put some reverb, and deaden the treble on the drums (not the cymbals) a bit so their snap doesn't sound so robotic, that or get EZdrummer. Second, the vox start after 8 bars, not 4, and well, the vox are, ehhh well, I guess I should be straight up and not pad it, they kinda suck dude, I mean okay I'm not one to talk because for the very LEAST you have proper equipment (I still record with a 1/8 mic for vocals, it's extremely hard to get a proper take.), but there's a lot of things missing for the vocals to be passable, for one, REVERB, or a very short delay (-50ms), whichever you prefer. The verb can give the vocals some depth and body, because as they are, they sound flat. Another thing is a smidge of compression, I felt some parts louder than others. The last thing is projection and actual singing, and that can only be achieved through practice. I might be a little biased because I used to shred my throat to this song and a couple of others from this album and era in metal, but I felt you could've projected a rawer, wilder voice, which would've helped the cover tremendously, as it is, well, kid I can tell you're not a day older than 14. I guess the last would be the bass, I found it too low in the mix, but I guess that's me nitpicking, put some mids on that motherfucker! Bass in that era of metal was felt AND heard, just ask Steve Harris, and pretty much every other NWOBHM Metallica ripped off to make Kill 'em All *COUGH*DIAMOND HEAD*COUGH* *COUGH*BLITZKRIEG*COUGH* *COUGH*TANK*COUGH*.
Other than that, I liked your rhythm tone, it's got punch, and hell, you got an interface and a decent modeler, that puts you directly in professional territory. The lead, well, it's got spunk, quite sloppy, but I guess that never stopped a band like Venom from recording. I apologize if I ended up shitting on the submission, but I don't mean any ill from it, I feel you've got quite some potential, but you gotta git gud.