Barn find carbine. Repair, conserve, restore or replace?

[Five.five-six]

This was kind of interesting. The first 5 rounds I put through it with some heat seemed to improve the bore every shot. The subsonic “tester” rounds with 7.0 grains Trail Boss were probably about 500 FPS. I could see the bullet going down range

My 27 grains of 3031 rounds shot at like 1,700 withe SD of 3.3 FPS and a SE of 8.2 fps

Then the 34 grain charges mapped like this:

IMG_0952.jpeg (94.29 KiB) Viewed 22 times

[butlersrangers]

Sometimes a rough Krag bore looks a bit better, after some firing sessions.
I've long assumed, that possibly hard jacketed bullets kind of scrapped, broke-up, and removed, some of the hard rust scale from the barrel.

I have shot enough rough bores to know, that sometimes, they retain surprising accuracy.