RCBS Neck Expander Die .309 . Needed to flare the neck a bit to load cast bullets. Also, can help with flat base jacketed bullets. Just like loading cast bootlits for handgun rounds. Can be used for any .308 caliber brass. I had used it to load cast bullets in a .30-06. A big help for easier loading. A lot of fun to shoot cast out of a centerfire rifle. Asking $15 Buyer pays shipping. Payment with a Postal Money Order.