I received a box of 40 S&W Grizzly Extreme ammo today. The box said 135gr and 1,350 fps. It is a brass/copper alloy bullet with four petals. I shot one through 4 layers of heavy denim into gallon jugs of water. The four petals open completely up and the distance between the ends of two opposing petals is one and five eight's inches. It made an empressive exit hole through the first jug and entrance hole into the second. However, it did not exit out of the second jug. As you will note by the surface area of the opened bullet, it probably would take a lot of energy to get further penatration. Interesting idea though.