10mm is king! I have all 3.. a .380 that stays in my pocket just as much as my wallet, and a 9mm that is used mostly for plinking, and a g20 10mm that puts a smile on my face every time I pull the trigger! I dont understand why 10mm isnt so popular and .40 short and weak is.. You can load 10 down to .40 power but why? I like the sting in my hand and the BOOM. Get a 10mm, and some doubletap 200gr and go put a smile on your face. I let my buddy shoot my G20 and I think he is going to dump his .45 and get a 10