I was of the understanding that the barrel weight was there as a reference from the time of proof and if the weight was different metal had bee removed and therefore the barrels were out of proof (I agree the choke shouldn't make any difference but forcing cone could as they are at the pointy end so to speak regarding pressure)
with regard to England I thought if you had the forcing cones done your barrels were reproofed? or maybe it is an urban legend? I had my barrels forcing cones a while back and remember seeinmg in the advert that the barrels were proofed after the work (which would have been hard when the barrels were all that was supplied no action went with them) this was from a "large" shotgunning gunsmithing franchise that has a shop in Australia (big enough hint without naming:))
intersting thread this I'm not trying to disagree with anyone just saying what my understanding was quite happy to be proven wrong
