But what is the profile of the BUTTON? Rifling in the bore is governed by the Button Profile.
ENFIELD rifling is 5 grooves, LEFT-hand, 1 turn in 10 INCHES, LANDS and GROOVES EQUAL width and Grooves quite deep. They were made using an ENFIELD CUTTER BOX which cut a single groove at a time, the Barrel turning to its 5 positions for each adjustment of the tool, the tool being adjusted to remove an extra .0004" or so with each adjustment. Generally, it took close to 60 passes to rifle a barrel.
That would be proper for a Wartime Number 4 (T).
The Canadian 6-groove barrels made on Bren Gun machinery came after the war. Also, they were BROACHED, all 6 grooves being cut simultaneously by a single multi-stepped tool about a foot and a half long which was drawn through the polished Bore. I can remember seeing these on the range in competition. I do remember, though, that they were awfully expensive: $65 for a new Barrel.... in a time of $10 surplus rifles and 50-cent-an-hour wages.
As far as I know, only the Americans used button-rifled barrels in any large quantity in World War Two, although I can be wrong.
Not trying to be a nitpicker here, but for a perfect duplicate rifle, the Enfield profile will be closer to original. I just don't know if anyone (apart from Ishapore and POF) can make one these days.