It is the aged-ass "carry the largest bullet in the sidearm with quite possibly the most knockdown ability you could tackle" argument vs . the "bullet sizing isn't going to make any difference as much as in which you can... Glock + Firearms Glock Firearms Glock 18C Pistol, 9mm Luger, https://glock-18-upper75285.mdkblog.com/32315869/getting-my-glock-18-parts-kit-to-work