Went to look at an interesting old double rifle being sold privately and took my scope with me.

So give me the read out on this picture?

I wish my .450 nitro was this pristine! Minor pitting on a bore that shows original rifling cutter chatter is how I read it.

Mine spent 70 years on a sealing ship killing seals in a saltwater environment, using black powder cartridges. it has pits throughout all the barrel, some of them real deep, and it will still hold less than 2 inches at 30 yards, where it is regulated to hit.

Hold on; how old is this rifle? Has it been rebarreled or sleeved?
Take a very good look at it.
Those are reamer marks and not a good thing at all, and since they are in both the lands and grooves, that means it was a button rifled barrel.
Cut rifled barrels will always show longitudinal striations, no matter how rough it was to start with.
A very bad one at that.
If it was cut rifled, the cutter would remove the reamer marks from the grooves.
If they were chatter marks, they would not be on top of the lands.
It's a mess.
Inspect it very well before you buy it.

Broach cut rifling? That was my thought.

A broach is still a longitudinal cutting process and does not leave cutter marks perpendicular to the lands and grooves. No way it could.
Broaches just cut all the grooves at once.

The gun was made in Suhl and is 75 years old.

That is interesting and puzzling. Does the bore show those marks all the way down? What caliber is it?

I've seen cut rifled barrels with chatter marks like this before, not quite this bad. I suggested broach because all chatter marks are aligned across the lands and grooves, suggesting they were produced simultaneously.

Used to be an old guy in Potlatch, Idaho, had an auto junkyard and scrap metal business. Built his own cable pull rifling machine and made barrels out of car axles. I had one in .22 hornet, looked like this, almost like someone had twisted a rattail file inside it. It shot amazingly accurately. Had a friend had one in .30 Krag, same story. I agree in general that a cut rifle barrel ends up with longitudinal scars, but chatter can make radial ones also. Usually not in the bottom of the grooves as evenly as this, though. Radial grooves are usually from the reaming and drilling and only remain on the lands, with the groove cutter removing them as you said.

WAG = Damascus barrel?

Hammer forged barrel could show those marks left in the bore from the reaming process, just like Remington and others that just drill, ream (if they do that) then forge. Any hammer forged barrels from Europe nowadays usually show a fine crosshatch from honing prior to forging. Those reamer marks likely won’t have too bad effect on accuracy, I’ve seen much worse shoot surprisingly well.

Looks like a Savage bore, but they shoot pretty well so I wouldn't worry about it.

The gun is a double rifle in 7 x 65R. It shoots heavier bullets to 2 inches at 50 yds.Gonna look at it again and will see how much of the barrel shows the chatter.

The chattered 22 hornet I had was mostly at the chamber end, that's why it shot okay is my guess, the muzzle was good.

I'd forgotten about that rifling machine. I looked at it when the heirs were trying to sell his stuff. I went to look at a lathe for sale and the rifling machine was next to it. Was made out of wood, built into the building, took up a space about 10 feet long.

To use, he clamped the barrel into the machine, ran a long cutter rod through the barrel, attached to the cutter head on one end, and the other end had a long splined rod that a gear slid on. A cable was attached to the end of the splined rod, went through a guide maybe 3 feet away, and then wrapped around a pulley, down to another pulley below, back to another pulley even with the gear on the splined rod but offset to the side to change cable direction vertical, up to another pulley to change direction horizontal and the cable attached to a chain that went over the gear. Attached to the chain end was a weight.

To operate the machine, a heavy weight on the end of the chain was released, it pulled on the chain, rotated the cutter head, and the cable pulled it through the barrel. Given the nature of the cable, splined rod/gear, and wood structure, it's easy to see how it chattered.

I'm inclined to agree with dpcd. The Germans usually honed the reamed bore prior to button rifling. Then cast hones and polished it. If it were cut rifling, I don't see how all of the cutters would chatter in an identical sequence. My guess is they reamed it and either didn't hone it or the grooves were too deep to completely remove. They don't seem to foul up very bad do they?

Ah! Matt said it and I had not considered it: Hammer Forged Rifling.
Here is what happened; they drilled it, using a dull drill and might have reamed it, but did a very poor job at that too. Then it was hammer forged, which, like button rifling, will NOT remove imperfections in the bore, but they will be ironed into both the lands and grooves.
Just like this one.
That is what threw me; if it was made 75 years ago, button rifling and hammer forging were both just getting started and perfected. Hammer forging was developed in Austria before WW2 but was not used until after the war. Not sure it was used during WW2.
The Germans are not always as meticulous as we think.
Anyway, it's not something to worry about; just cosmetic. The cutter marks are smoothed over and won't collect much/any copper.

Here is a new Lothar Walther barrel...still in the box. Similar??

No; LW barrels are not hammer forged if made in the US. And Yes, they are similar; button rifled after using a better reamer than the Suhl guys did. Theirs looks like they just drilled it and made a barrel.
In both instances, the rough bore gets impressed with rifling, but the imperfections remain.
Doesn't mean they won't shoot ok.

Were not LW barrels hammer forged until just a few years ago?

Maybe until they moved to the US state of Georgia.
They are just a new company making button rifled barrels and offer nothing new. Just because they use an old German name doesn't mean their barrel making lineage goes back that far.
I refuse to use them.

I happen to REALLY like a quality hammer forged barrel. I have a couple LW’s recent CHF barrels in 308 1-10tw and they are gorgeous in finish and shoot extremely well. The problem in the US is getting a good quality one as the forging process is used for its high production aspect and not for the precision it can offer. Also bought a bunch of close out Heym blanks from Numrich that exhibit the same high quality.

Anyway, when you state the rifle is 50 years old, I believe by the early 70’s Europe was pretty heavily into hammer forging a large portion of their rifle barrel production.

Are those US made?