Does changing the barrel on a bolt action also change the chamber?

[LoonWulf]

Apparently chambering. Guys have attempted to fix the problem by modifying the magazines. Some have had some success with that some have also polished the chambers and other things to attempt to get them to work.

It sounds like it's not a chamber issue so much as an issue of how the rounds are presented to the chamber.
The Americans have a flat face on the back of the barrel, that rounds can hang up on.
The mags can also hang up rounds due to the very short "ramp" in them. I'd be curious to know if the AR mag RAs have similar issues.

A chamber issue would be something like you got the round in but can't close the bolt, or light strikes, case head sperations etc. The chamber mouth DOES guide the round in, but you can't really modify it much to improve function from the mag.