Picked up a mid 70's era Stevens & Savage model 79 for cheap and it seemed in good shape but after taking it out to trap shoot with the bolt does not unlock after firing. You always have to press the bolt release after every shot to cycle the bolt. Dry firing it functions as it should but when you fire a round it will not unlock on it's own. I've stripped and cleaned it and everything seems in order, doesn't appear to have many rounds through it. Very frustrating issue. Hope someone out there can lend some assistance. 
