Easy to be super serious about this when you wisely avoid fighting any wars.The Swedish Mauser Armorers usually stamped the serial number on their new parts if they had them. Or, if they had good parts from scrapped rifles, they would refit and headspace bolts. Then stamp over with the correct rifle number. They were super serious about rifles at all times. hoot incredible groups even today. And are 6.5 X 55 caliber. Pleasant to shoot for an old guy like me. Never a sore shoulder if I shoot some of mine all day long.
The 6.5 X 55 is pretty much the Granddaddy of all 6 mm type of cartridges. Popular caliber even today.
In NRA Vintage Bolt Matches, you see quite a few and they do very well!