From my experience, with a ZKK vs a Parker Hale M81, a BRNO has a much BETTER QUALITY chambering job. Indeed rounds that are full length sized to chamber in the P-H are stiff to feed and chamber in the BRNO.
Not because of headspace being less on the BRNO but because the chamber is tighter all around but especially at the case sides just below its shoulders.
My advice use a tighter set of reloading dies say RCBS or the newer, excellent, Redding. Also paint a dummy round with engineers' blue to show any "rubbing" on the action sides as the cartridge goes from the magazine to chamber.
When your BRNO was made it was made to tight tolerances. It deserves ammunition constructed similarly. I'd bet it works OK with Sellier and Bellot ammunition.
Not sure mate what does the term 'chambering' actually refer to? Is it the bolt closing ok onto the round in the chamber?
If so the rifle chambers ok, it just doesn't feed the round 'to' the chamber ok. Although it may do now I've tweaked things I just haven't had chance to try it yet!
Cheers
surely one reamer is not the same as another!
depends entirely on the spec they cut it to and the number of chambers it has cut I would have thought. Old reamers make smaller chambers...not bigger ones
I have 3 rifles of the same calibre and another that I load for within reach and they all have different chamber sizes
A Caledonian (John Dickson)
A Parker hale
A BSA
A Mauser
chambers size in increasing dimensions
neck sized rounds from the Caledonian fit everything, neck sized rounds from the Mauser fit nothing...except the Mauser