Question: is 40 caliber better than 9mm?
Answer: 40 S&W is essentially just a short 10mm round, it features higher breach pressure than both 9mm and . 45 ACP. It's a heavier round. ... But, if you spent an equal amount of training resources working on shooting the same handgun, chambered in 9mm, you'd probably be faster and more precise with the 9mm in the end.