feed problems on DPMS LR-308

[joe from MO]

I just acquired a used but like new DPMS LR-308 Ser,# 170XXX.  I have tried LC match, new Federal and Winchester ammo with the same feed problem. Most of the rounds go about half way into the chamber and stick there.  The forward assist will not push the the rest of the way in.  When extracting the live round I see shaving and scuffing at about 3 to 6 o'clock on the case about half way down the case as viewed from the rear.  The rifle is clean and well oiled with no apparent wear.  When I inspect the chamber it appears that the chamber opening has a protruding edge around the chamber near where the cartridge head would seat. That ridge is all that I can see that could be causing the shaving.  I called DPMS as the previous owner said he shot it little and had problems.  But DPMS did not want to do much but sell me another barrell.   Any one else had this problem?  Any suggested solutions?  

[hiprimer]

Post some pics

[392heminut]

If the chamber has a burr find a local gunsmith who has a 308 or 7.62X51 chamber reamer and get him to make a light pass in your chamber with the reamer. That will take care of any burrs.

[crowbait]

Try dropping a round into the chamber.

[shooterrex]

Pics would help. Will the bolt close on a round inserted into the chamber? How many different magazines have you tried?