At the local shooting range a fellow was shooting his new 597 in 17hmr. He was complaining about it shooting all over the target. After he had shot about one and one half boxes of the Hornady shells one made a dull thud sound. Several parts of the action blew out the bottom of the magazine. We found the mag spring and othe parts of the action. The shell we took out of the rifle was split almost all the way down to the rim. We looked at some of the other shell he had fired before and about 1/3 of them were split just past the shoulder. He was upset and I did not get a chance to see if the barrel was clear or not. Don't know if it was the ammo or the rifle at fault. He sent it back to Remington so I should get a report and will follow up when it comes in.