I have a brand new semi-auto CMMG LPK in my brand new lower. It hasn't been fired yet, and in dry fining, the trigger is awful. It feels like the trigger is trying to be two stage, but is dragging on something and feels like a god-awfully creepy single stage.

Is this usual? I've never built a lower before this one, so I don't know if it just needs to be broken in, or if I should take it to a gunsmith for tuning, or what. I tried taking it out and reassembling, but it didn't fix the problem.

Any advice?

Go get some 1000grit sandpaper. Then use it to polish the engagement surfaces of the trigger. It's just surface hardened so only make a couple passes. This should smooth the trigger out and remove the grit.



A polishing stone is actually a better tool to use, but theyre harder to get/more expensive.

If you still want your trigger to feel better then get a JP leightweight spring kit for it.



If your uncomfortable doing the work yourself, then send it to Bill Springfield at www.triggerwork.net

My RRA single stage is gritty/creepish too, as is my father's. I would think it's normal. But i'm no gunsmith.

Bob

I've had Colt's that were gritty and DPMS's that were smooth. It doesn't take much for the trigger to feel pretty bad. I just polish them out if they don't feel good.

Take it out and shoot it.

Triggers will often smooth out with some use.

+1 on the above.  Go easy with the sandpaper.  You don't want to go through the hardening.  



After the passes with the 1000 grit, grab your trusty Dremel and the soft fabric polishing wheel.  Polish the engagement surface with either JB's Bore paste or Flitz.  Polish it until it shines and is smooth.  I polished the triggers on my ARs to a mirror finish.



Makes a huge difference.





 

Shoot it first (or dry fire) and maybe add some good grease (maybe add a little lead dust to the grease). Sandpaper, though it will work in the short term, would be my last option as it could potentially cause problems either with extended use or due to home gunsmith's error.  

Does anybody know for sure exactly WHAT SURFACES are "surface hardened?."
I've got a feeling that the ONLY surface that may be surface hardened is the face edge of the trigger.
I've got a feeling that the hammer and disconnector are not surface hardened at all.

Everybody raves about Bill Springfield's work, and I have every reason to trust his reputation.

But, take a look at the edges he modified, and explain this in the context of "surface hardening."

Here's the link to a bunch of pics:
You will see the surface-color difference on only the trigger.
http://www.ar15.com/forums/topic.html?b=3&f=118&t=456282

I can't vouch for the origin of the parts. They are take-offs from a "parts-gun" I bought from a friend.

Here's a pic of the hammer.
(Since Bill worked on the set these parts have not been installed or tested in any of my equipment yet.)