Once at my local gun shop there was a PH trying to exchange his Rigby .416 for a push feed Winchester in .458. If memory serves, it was a double bridged mauser action.
I believe it was 1980 and he had exhausted his stock of Kynoch ammo, the last of which would missfire occasionaly, and could not find any.
He would get rid of the gun for the new Winchester, or even pay something on top, I am not sure... The shop owner would not want it, and I refused it as well, ignorant as I was. I do not know how the story ended, but every now and then it comes to my mind.