Our 130 grain, full bore, .410 SCREAMS out of an 18″ barrel at 1,520 fps and yields 670 foot pounds energy. THAT compares directly to a .357 magnum which is more than enough energy for deer sized game. The slug is identical in shape to the Lyman 12 gauge, 525 grain slug and the typical .177 match grade pellet which gives it vastly superior accuracy to the rifled slugs currently on the market. While there is another slug out there that alleges to have a heaver weight slug, they are kind of cheating. You see, they are including the weight of the wad. that wad weighs nearly 1/8 ounce so you are really buying a 1/4 ounce slug. What you are buying is 25 rounds of .410 Thunderhead slugs.