okay guys, maybe someone can help.

I installed the RRA 9mm hammer since I have a 9mm upper and now with it installed, I cannot pull back the charging handle after the hammer comes forward. It appears to be causing the front end of the bolt carrier to rise a little which in turn causes the rear end of the carrier to bottom out and hit the buffer tube threads.

Any thoughts?

It worked fine with the DPMS hammer installed (should I switch back?)

Disregard, just found the answer on page 2. I am a douche.

What was the problem?

Ahh, I'm sorry, I should have posted that.

Apparently when your bolt carrier is already ramped there is no need for the RRA 9mm hammer I installed. Apparently, the bolt catches on the notch on the front of the RR 9mm hammer and they are not compatible.

So.. switched back to my DPMS hammer and life is good.

same here....once I took everything back apart and took a look it made sense. I'm just glad I saved all those old parts :)