i see that powder valley has 9mm 124 gr hollow base round nose. what is the intended purpose of the hollow base? link below for photos
www.powdervalleyinc.com

Berry's Bullets .356 Diameter (9mm) 124 Grain Hollow Base Round Nose
Berry's .356 / 9mm 124 grain hollow base round nose thick plate bullets from Powder Valley are popular with pistol reloaders. Shop 250 and 1000 ct boxes today.
