Jess - nice find. I was seeing some like that out west last year and in the same price range. I shoulda, hadda, outghta got one.
I've shot two groove barrels before, Springfields and SMLEs, and they are good and accurate. All mine, whatever the bore seemed to prefer the heavier slugs, 180s in the 06 and the same in the 303s, but both seemed to shoot just about anything equally well.
I think you just have to get that honey out to the range and see what she wants to do............JMTCW. Mikey.