Dan Wesson
Hi Boo and welcome to the forum. I couldn't decide whether to get the 4.5mm or 6mm version, but I had a think what I wanted to do with it. Sometimes it's necessary to shoot indoors because of the weather so I got the 6mm one. I can shoot up the hall from the kitchen and knock over old empty shotgun cartridges, plastic soldiers etc and the only backstop you need is a cushion or two! Of course, when you get one calibre you will want to get the other as well, so it doesn't really matter which you buy first. Enjoy your shooting!
Life is to be enjoyed, not endured.