Here is what has happened in the past week, and how to fix it if it happens to you.
Bought a new Ruger Precision Magnum rifle, 338. I know, I never buy factory rifles, but I did.
Been shooting the 338 Lapua for many years in my ArmaLite AR-30 (first one made), using RCBS dies, without issue.
Chambered a sized piece of brass in the Ruger, and had to force the bolt handle down. Yes, I had resized it well, with a good cam over on the Chucker press handle, so it was sized to the max.
Bolt handle would not open, so of course, I grabbed a block of walnut and smacked it open. Case stuck in the chamber, and extractor broke. Actually tried three cases.
Punched the case out with a rod; short story is that Ruger chamber is .0015 smaller at the base, just in front of the solid head, than the RCBS die makes the brass. New Lapua ammo fits perfectly.
I ordered a Hornady sizing die, which arrived yesterday.
Called Ruger and they are sending me a new extractor free.
Sized all my brass last night, they all fit perfectly.
Lesson is that, sometimes (not very often; normally dies are made to fit all possible chambers) tolerances between die and rifle makers, overlap a bit, causing a small issue. Which is why you always check the chambering of sized brass FIRST; before you do any loading. Saves a lot of guessing.
Now you know what to do.
Case closed.

10-4 roger

Dies and chambers vary in size, look at the SAAMI cartridge and chamber drawings. The plus and minus tolerances for the case and chamber can be amazing.

Example, I have a standard Lee .223 die that will size the case diameter smaller than my RCBS small base die will.

And forcing the bolt closed on any rifle is not a smart thing to do.

Yes the tolerances between min brass and max chambers is positively huge. It's a wonder that anything fits correctly.
Forcing bolts closed? I don't recommend anyone else do most of the things I do.

So- now we get to the real question..How does it shoot, Tom? I just read the article in American Rifleman. Like to know if you get similar results.

Was stuck brass fired in th AR?

I am going to wait for the new extractor; I could always punch the brass out from the muzzle but it has been too cold anyway. If it is anything like my RPR 6.5, I expect .5 MOA.
Be aware that it is a very heavy rifle at 15 pounds, and with the huge muzzle brake, it will not recoil at all. Not as big as the AR-30 brake though, and that has 243 recoil.
Brass fired in the AR-30? Yes. The Hornady die sizes them adequately; the RCBS one, didn't. Ruger chamber is below SAAMI minimum at the base.
The Ruger chamber is actually less than .0005 larger than a Lapua factory round.
Chambers are allowed by SAAMI to be .5893, max. Both rifles are yards below that.

This is the only cartridge I had this problem with too.