I have a new, current-gen (MLOK) Ruger Precision Rifle in 308. I did absolutely nothing to it out of the box besides mounting a scope and bipod on it. When I shoot it, I can rotate the bolt up to the unlock position, but I can't pull it back without a lot of force (think "smack with mallet"). Feed, extraction, and ejection seem otherwise fine. This happens with genuine M118, 168gr FGMMs, and Silver Bear, so it doesn't seem like it's ammo-specific. The brass looked fine when I inspected it; no obvious marks, bulges, or rim issues. Primer didn't look like it was overpressure.

Anyone have any ideas on what's wrong and how to possibly fix before I contact Ruger for an RMA?

Any idea what kind of finish it has on it??  Maybe take a cloth wheel and a fine grit polish to it?

How many rounds though it?

Does it act like that with NO ammo in it?

I think it should go back, Before you do anything.
I mean what if you try to fix it and it makes no difference then send it back, I could see them blaming whatever was done on your end.

I'd send it back.  Mine is slick as snot.

To answer the questions:
1. Five or six rounds through it, all with the sticky bolt problem.
2. Bolt finish is their standard black coating. Bolt face has no obvious problems.
3. Works super smooth with no ammo in it.

Honestly, I'm just more mystified at why this is going on. I am leaning towards a screw-up on reaming the chamber causing just enough overpressure to cause these issues. No idea how it passed test-firing (I suppose I am optimistically assuming it was test-fired).

What happens if you eject a live round?

My Gen3 6.5 is smooth. I have used Hornady 140 ELD Match for precision and Sellier and Bellot 140 grain for practice (1 MOA lower than the Hornady) and the bolt is smooth after probably 700 rounds. Only issue I have had is safety selector came loose.

Decent question.
Bump.

Just following back up on this: I got my rifle back from Ruger, and they said they replaced the bolt assembly and the barrel amongst other minor things. So I rather suspect it was indeed a chamber or headspace issue. After I shoot it on Sunday, I'll report back on whether it solved the problem - will say that snap caps cycled cleanly through it, which seems promising.

I'll bet they paid a little extra attention to it during reassembly.  This may become the most accurate rifle in your collection.  I'm glad Ruger made it right.

They sent me a 50yd test target that definitely shows it being capable of sub-MOA. I'm just not that good (and I was running it off a bipod), but my FGMM went where I thought it should... and extracted effortlessly. So pretty happy. Looking forward to using it in a class next Sunday.

ETA: shot it at the class, it was shooting better than I could ask for.