I just ordered my barrel from Rock Creek last week. Its going on my 40xb. Remington varmint contour. Apparently they are putting 5r cut rifling in these. Last time i had heard they were using 4 groove medford rifling. Does anyone here have one of the 5r's? How does it shoot and what ammo does it like. I just bought some lapua center-x and eley match to try in it once i get it back from brian voelker. How you guys liking your rock rimfire barrels?