Brand new Daniel Defense Upper problems

[samurai_sam]

I wasn't really sure where to put this, but this looked like as good of place as any. So I picked up a Daniel Defense upper brand new from Jensens on monday, and I slapped it onto my LMT lower. When I chamber a round (using HSM reloads which have fired fine through my other AR) it jams. I have to pull on the charging handle with both hands to get it to eject the round. I thought maybe it had something to do with the lower, so I seperated them and im still having the same problem. When I eject the round, the bullet is marred from what appears to be the feed ramp making contact.
The upper says its chambered for 5.56, and im trying to load .223 in it. Could this be the problem? Or should I just take it back to Jensens and have them look at it?
Thanks
-Sam

[BadShot]

I'd run it back to Jensens, something is off kilter. DD makes a good upper but as with everything some times bad apples slip by.

[Hoser]

Did you clean the barrel yet? Sounds to me like the chamber might be a touch dirty.

The scuffs you see on the bullet are going to be there no matter what. The bullet has to go up the feed ramps.

[samurai_sam]

I went and picked up some Black Hills ammo and the rounds feed through perfectly. I guess its just picky on the ammo.

[Great-Kazoo]

IF you feel comfortable/mechanical enough lightly polish the chamber.
i have needed to do this to a few new bbls on different rifles and handguns when using a new bbl. tac solutions bbls also a new BM 11.5 out of the gate was required before running the different ammo i shoot.

[LIL-COMMANDO]

Is this upper a complete DD upper with Carrier Group? I ask because some companies advertise DD upper but when you look closely they are selling the DD barrel with a non brand upper and a non DD carrier group. I ask sice PK firearms sells a complete upper but when you read closely it only had a DD barrel in the group.

I am waiting for my complete DD upper from Aim's and for $499.00 Im anxious to shoot it. I also will be using a LMT LEO marked lower.