Also, comments in the thread about a sleeved gun being out of proof are anecdotal. First of all there arent any Proof Houses in North America. Secondly the new barrels used in the sleeving process can handle any modern ammo.
Is the gun in question American-made? If so, then your point may be correct (although most US makers did their own proofing). If not, you would need to consult the proof house rules for wherever the gun was proofed to determine if it still in proof after sleeving - sleeving certainly requires re-proving in the UK.
