I agree with you entirely Big Duke. But what do you say to thread 17 where we slimmed down a brand new L4 barrel, sleeved the gas port hole and are still using it as a 7.62mm No5. Given that we had the facilities to use it on the Enfield layer/remote firing for the first 10 rounds. Didn't re-proof it of course. I worked on the practical side that it started its life with a sleeved over gas port and although it's slimmed down, the gas port is STILL sleeved over but un-vented this time.