Is it feasible to 'improve' a 303/25 chamber without setting the barrel back and recutting the throat? Meaning, simply opening up the case body area of the chamber, without touching the neck area. Is there much risk of chamber misalignment? Would using a lathe and a suitable reamer ensure concentricity?

I not yet checked to see who has what kind of reamer and I have not yet decided to take this step. I most likely will not but I would just like to know anyway.