I just bought a pre-ban olympic arms CAR but there is one problem, the bolt carrier is pretty rough. It looks like like it jammed and someone took a screwdriver and hammer to it. My question is; Which is better to replace, just the carrier or the whole bolt/carrier assembly? Any help would be appreciated.
                    Thanks

If it functions fine, do not worry about it. The previous owner may have stuck a round in the chamber, and used something to move carrier back and unlock bolt........got a pic?

Sorry I don't have a picture. The marks are on the bottom of the carrier. If you have the bolt closed and you look up into the mag well they're about a quarter of an inch back from the front wall of the well. Any ideas of what could have caused that? Thanks.

I would just replace the carrier itself for two reasons,
1. Cheaper
2. The bolt is "mated" to the barrel, a new bolt may have head spacing problems if the rifle has been fired quite a bit.
As for what caused the scratches, I'm not going to guess, since I haven't seen the damage.
It coud be from prying the bolt open, to having been dropped.

I reloaded some PMP ammo that caused me some massive problems...it jammed every gun I tried it in, including my bolt rifle!!  Even though the case looked good, had been full length resized, and checked out in a case gauge, it still was too damn big.  

I though I weeded it all out, but I got a couple of straglers stuck really bad.  We had to take a mondo screwdriver and pry the bolt back from the mag well. It put some very small scratches on the bottom of the carrier, but not enough to make any difference.  

Thanks for your help I just ordered a new carrier for it. Thanks again.