This giant brick of a revolver fires .22 caliber??
Look at it. Look at how tiny that bullet is compared to the gun itself and his hands. That's not an animation mistake, that's pretty realistically sized.
Fox and I had to pause here and back up to make sure we read it right - .22 caliber (5.6 mm) is generally used for light target shooting or pest control. It's a varmint gun. Most personal protection sidearms use at least a 9mm round, and Vash's revolver in the 1998 anime and manga used the even-larger 45 long colt.
A .22 caliber pistol isn't going to do a lot of damage against a human opponent. Yeah it'll hurt, but you'd have to try pretty hard to actually kill someone with - ohhhhhhhhhhh never mind I get it now.
This is a great new little detail that fits Vash's character super well.
"Now, we're not looking for any trouble, y'hear? We're 'round these parts to do our business, just like how you're here to do yours. So how about we all act like civilized folk and you set that gun of yours down before something... bad happens."