The bore condition disc, IF it is original to the rifle, will tell you about the bore.
But you must remember that what the Swedes thought needed replacement was about where most countries started as new... The Swede were super anal about their rifles.
The barrel has probably been replaced as that rifle was arsenal rebuilt over the years. They used them until the 1980s.
I will explain the disc in an update , the wife is yelling at me to come into the kitchen...
OK , I'm back..
In the largest area, see how there is a stamp over the zero. That means the bore on this 1900 Oberndorf made m/96 was exactly 6.50mm.
Then the next largest area deals with over or under shooting after the sights were modified later for the 1941 ammunition. This rifle has 0 over shooting.
Then the smallest area is the bore condition. This rifle has no mark which means it is a virtually new or like new bore.
A mark over the 1 means the bore is still very nice but not new. A mark over the 2 means some wear. Over the 3 is more wear and they might think about replacing it one day down the road.
IF, they had a bore that really needed replacement, they pulled the disc and filled the hole with red wax until it was re-barreled.
Bore disc are often not original to the rifle and they are often phony copies found on e-bay.
$300 is a GREAT price for a matching 1900.