You might consider , as an option , before replacing your barrel , buying some David Tubb " FINAL FINISH " bullets and loading / shooting them through your rifle to fire-lap the throat and barrel .
If you purchase the full kit , I think that you receive 5 different levels of bullets coated with his lapping compound , from coarse to very fine .
I have used them on 4 different rifles , in 4 different calibers , and had excellent results on all 4 . One of my rifles had the throat looking very similar to the first photo that you posted . After using the FINAL FINISH bullets as directed , the throats smoothed-out very well .
Each of the 4 different rifles now are much easier to clean , and do not copper-foul as they had previously done , and accuracy improved .
Try calling him at his company , Superior Shooting Systems , in Canadian , Texas , and ask his opinion if these would help .
DMP25-06