The two-groove Lee Enfield was pretty symmetrical. I am under the impression that one groove was cut at a time. If so then it is conceivable that a fault occurred on that particular barrel (or batch?). It might be worth double checking that bore.
I have three two-grooves, one is mint the other two not so much but the one I shoot with is very accurate. I'm told that the mint bore is very accurate too (I've only shot with the one). All three are very symmetrical.