It could be one of two, most likely.
Either "A/S Raufoss Ammunisjonsfabrikker, Raufoss, Norway" or "Remington Arms Co, Bridgeport, Ct."
If it is Norwegian it should also have the NATO cross headstamp on it. It is supposed to be very good brass.
If just plain RA without the NATO cross I would go with Remington Arms.
That my 2/100ths of a dollar worth on this one.
bob