2,000fps load with a 270gr. bullet produces VERY mild pressure in that case with most ANY powder that would be used. Even my Model 96 9.3x57, which has a smaller capacity case, produces 2,300fps with that weight bullet and still low pressure - with no adverse pressure signs what-so-ever.

When the pressures get up to normal operating ranges, the 'bulge' at the web will run more evenly around the case - normally, unless your chamber is cut improperly and "all wonky".

Marks, ie: scratches in the chamber must be removed, unfortunately, this can only be done by removing material, making the chamber even larger, to the extent of the depth of the scratching.

The best case scenario would be to set the barrel back one full turn (about 1/10"), then re-chamber it to adjust the headspace. This would probably eliminate the scratches - IF they are at the web location right now.

Scratches on the body of the chamber indicates a case head was likely blown off due to over FL sizing (creating excessive headspace with THAT case) or excessive headspace in the chamber & normally FL sized cases.

To remove the stuck case, someone who should not have touched this rifle got in there with a screw driver or too large a tap, and scored the chamber walls.

When pressures get up to the normal operating range, the brass will likely expand into the scratches and refuse to extract normally.

Just a guess on what's happening with that rifle.