in my 10mm RIA i've shot more 40s then anything else. Why didnt I just get a 40 as I'm sure many will ask. Because I got a great and I mean great deal on my RIA 10mm that I couldnt say no to. I know I can crack my extractor do damage to my gun but so far I have had no problems there. I load my 40s long so they dont have to "jump" as much in this long chamber. If I had to do it over again I would still get a 10mm. I like shooting stout 10s but you just cant do that all day so 40s are great for plinking.