This RNFP (round nose flat point) 40 calibre lead bullet is 0.401″ in diameter and measures approximately 18 on Brinell.Western Metal is carrying a large supply of lead bullets for the Canadian market. All of our lead cast bullets are hard cast using a tough, consistent alloy. With our alloy, and bullet lube, you receive a very accurate bullet that leaves very little lead in your barrel. Hundreds of our lead bullets can be fired without any loss in accuracy and without cleaning your barrel. Our tight weight tolerances make this a very accurate bullet for the reloader.You won?t be disappointed in this product.