Just last week a friend bought a used Savage heavy barreled 223 varmint rig. First thing we did was run the scope down it--while it wasn't too dirty, some streaks of copper and a few spots that were darker brown smudges, what was alarming was the tooling chatter marks the entire length of the barrel. I mean the lands looked liked serrated knives. It looked horrific to me compared to almost every other rifle bore I own.
We put a scope on it and went off to the range. His first five shot group at 100 yards off the bench was .34 MOA with Hornady 55gr Vmax (see below) factory loads. Further groups right around a half inch. Fed gold match 69 gr BTHP factory rounds around .6 MOA. Even some rot gut AR plinker loads with 55gr cheap FMJ bullets were right at an inch.
Now, maybe this thing will foul like crazy and accuracy will not last once it starts to get dirty, but my point, as noted many times above is to let the targets be your guide, not what you see inspecting the bore! I can tell you from experience, the pics in your original post are of a VERY clean and quite smooth bore. If it's not shooting decent groups the problem very likely lies elsewhere.
A little off the OP but:
Also, when you check your zero a week before your hunt, DO NOT clean your rifle until after the hunt. For hunting you are mostly concerned with first shot cold bore accuracy. When I have a big hunt coming up I go to the range about a week or two before the hunt. I put up a target and shoot ONE round. Put the target back in the truck. Go out a day later, put up the same target, do it again. Then once more. I feel that at that point I have a three shot group that represents realistic accuracy for hunting. you can make this as elaborate as you want. You could fire two shots each time to see change in POI from first cold to follow up shot. You could do it from practical shooting positions, longer distances, whatever. Of course if your hunt is at a significantly different climate/elevation then you should check/adjust zero when you get there, especially if your rifle has been bounced around in an airplane cargo hold.
OH, and at the risk of starting a keyboard war, soft bronze brushes in no way damage your steel bore. Although I've not found bronze brushes necessary to get my smoother (custom vs factory) bores clean. Just use a good bore guide and a stiff rod so that it all stays concentric to the bore.