Shop › MAG FN 503 9MM 8RD BLK MAG FN 503 9MM 8RD BLK $43.99 FN America Magazine, 9MM, 8 Rounds, Fits FN 503, Black 20-100261 Add To Cart Added! FN America Magazine, 9MM, 8 Rounds, Fits FN 503, Black 20-100261