A pal of mine had a BAR in .458, but IMHO he spec ed the barrel too heavy, and it was not unlike trying to shoot a heavy varmint rifle off hand. Still, the rifle was reliable, accurate, and a hoot to shoot. I probably put 100 rounds through it, and recoil while strong was far from unpleasant...if I recall the trigger was a might squishy - but that's the nature of the beast. It was put together by a Canadian gunsmith who has since retired, but as posted above, the conversion should not be beyond the ability of a competent smith who is familiar with the BAR design.