I have been working with a 22BR in a LV for close to two years. Does not shoot like my PPC rifle. In defense of the cartridge the reamer maker made a mistake and ground my reamer neck ,254 instead of ,244 and the gunsmith just went ahead and used it anyway, I did not find out till the gun was shipped to me and the barrels were to short to rechamber, I have triied my best to make something out of this but no luck, I also had a 1-10" barrel made at the same time, but not uded yet, Anouther possible reason it may be hard to make it shoot is the Lapua BR brass has water overflow capacity of 41,1gr and for instance a ,22-,100 case made from Sako USA cases has 28.7gr to overflow.
My 22BR shoots best with handmade 52gr bulets and slow powders like Varget and AA2520, I've been thinking Win 748 outta do well also,
Tim J,