Thread: Stick a bullet in your muzzle?

When I was a kid I saw some old blokes (when they were looking at .303s), hold a loaded .303 cartridge and push the bullet ogive into the rifle's muzzle.

Over the years I've seen it done a few other times on .303s... guessed it was to check how good the barrel was due to how much rifling had been worn down by the bullet.

However I know now, that a bullet going down the barrel isn't what causes a barrel to wear out. It's the heat generated by the burning powder ahead of the chamber. So it's only the throat and start of rifling that 'burns out', not the rest of the barrels rifling.

So has anyone seen this 'bullet in muzzle trick' done before?... and what is the actual reason for it?