Keep in mind that Metford rifling in the Lee-Metford rifle performed well when it was shooting black powder cartridges. The Brits started to encounter barrel life problems when they changed to smokeless (if you can call it that) powder charges. They were shooting cupro-nickel jacketed bullets, with cordite stick powder, and corrosive primers, out of barrels made from nickel alloy steel. The deck was stacked against Metford rifling. Conventional rifling performed better under those circumstances. The Lee-Enfield rifle is basically the Lee-Metford rifle with conventional rifling.
With modern powder and primers, current steel technology, soft waxed lead bullets, and low pressures associated with rimfire cartridges, we see this rifling performing comparably to the current crop of MI rifling styles in terms of barrel life.
Good Luck with those barrels Jr., give us a report when you have had a chance to do some shooting.
James Lederer
Rock Creek Barrels