This suprised me, but a level 3 carapace gorge can actually kill a single full health unupgraded LA marine a good amount of the time. I've found that with a combination of erratic dodging and heal spray you can actually take down a rambo gorge hunting marine. What usually happens is they come and empty their LMG and pistol at you without killing you, while constantly taking heal spray damage. It's got a very impressive range (far beyond the graphic) and good rate of fire. This combined with with incredible protection carapace gives you can really tip the scales in your favor. They should die right around the time you're out of energy.
Sometimes they'll try to close in with the knife after they've spent their guns, which is good for you since you can erratically back away, continuing your healspray barrage. Also, maybe some people will frown on this, but bunnyhopping is really helpful in this aspect.
I guess this is more of a "do-or-die" tactic than redemption, but it's a little more fun and you just might save an RT or two this way.
Perhaps it doesn't work against marines with impeccable aim, but has anyone else noticed this?
your != you're