Happens to me constantly and it's not you that's inconsistent, it's Destiny's mediocre multiplayer. I say mediocre because Bungie manipulates how well or bad you'll do. Pay close attention to how you're getting your 1v1 kills with primaries. Use the same primary weapon for one week in normal Crucible. By the end of that week you'll be able to tell how well or how bad you'll do within the first minute of the match. You will start to notice those matches with 25 kills/4 deaths with say a scout rifle are 3 body shot kills or 2 body + 1 headshot. At the other end where you do horrible you'll see 8 shots only causing 50-75% damage with that same scout rifle. There's also a middle ground. That match you get a 0.9 to 1.3 k/d. The game seems to be working like it's supposed to. No 3 bodyshot kill, it now requires a fourth bodyshot. From my experience, those are the most fun matches (the lead constantly flips) that win or lose it finishes with a 1000 point or less difference........ And you just want to play that team again.