Failure to go into battery

[ecosystem3]

I recently finished building an upper with a Monster 20 Barrel and bolt from a recent group buy. I took it to the range this weekend to test it out and it failed to go into battery on the first try. I placed one Prvi Partizan 6.5 Grendel Ammo 120 Grain Hollow Point Boat Tail into a magazine, placed the mag into the lower and released the bolt catch. It sounded like everything went well. Pulled the trigger and "click". I went to pull the BCG back and reload but it was jammed forward to the point I had to use a mallet to disengage the BCG. I tried it again and the same thing happened. I cycled the BCG without a round and everything work fine. I am able to place a round into the bolt first, I am able to move the BCG into battery but I'm unable to do so from the magazine. It's almost as if there's not enough room for the extractor to open to receive the case before it goes into battery. There are scratch marks on the extractor.

Any thoughts?

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