[quote=@Banzai Tracers] I thought that both the 6.8 and .40 and 10mm came from the... taka taka https://en.wikipedia.org/wiki/.30_Remington So you can neck down any larger into a smaller. But not in reverse. That dog wont hunt. Yes, i was aware that carrier tilt was a general problem plaguing ARs, i thought i'd get away with it for a while and didnt want to make the budget list into indevidual rifle components, thats why i included a littel redundancy, but HEY! I have a CNC that can make carrier shims or whatever. I notice you hate the .40 :) i dont. And i think ive stolen a bit of a march on you. Heres my thinking. No Civilian or police pistol caliber will penetrate body armour these days. So what do they have to penetrate? A glass windshield for a start. So what do you do when your using a 9mm? Go up to 147 grain so it penetrates and doesnt dowhateveritdoes? But the 9mm loses some of its appealing characteristics when its as heavy as 147, range for one. Do you know what round has all the benefits and none of the drawbacks? Its the [s].357sig![/s] ofco... i mean the .40+P! The .40 already has a projectile thats ~145gr and can fit enough powder to make sure it goes through that glass/wood/cardoor. Infact with a .40 you can make it replicate any caliber from a 9 to .357sig to light 10mm load, without having to switch platforms. I dont hate the .40! I hate the 9! [/quote] You are right about the .40 and the 10mm and the 6.8 SPC! I am so sorry. Please forgive my ignorance. I hadn't done my due diligence on the 6.8 SPC except to know that it came in SPC and SPC II and that it was better at close range than the 6.5 Grendel but worse at long range. I did some digging, and you are right- both are made from the .30 Remington. I am so sorry for putting my foot in my mouth, and I genuinely appreciate the opportunity to educate myself. Well done, sir. And I will agree that the .40 is versatile (much like my .300 BLK), but I still can't get over the lack of magazine capacity and muzzle flip for the tiny boost in power (in factory ammo, hand-loading is another story, but you reload other calibers to better powers as well). I actually like a 154gr Federal HST round in a +P 9mm for most of the work I feel I need to do. And if I think I'm going to need penetration, I stagger in 124gr FMJ loads. If I want range, I'll bring out my .300 BLK SBR. Edit: [quote=@Irredeemable] [@Andrew Blade][@Banzai Tracers] Alright folks. You can put the firearm dicks away- no need to bring out the rulers as well. [/quote] I don't think you have to worry, Irredeemable. I don't think he seems the type to get butt-hurt about someone disagreeing with his opinion, and I'm certainly not, nor am I one to argue a point when I can just do some research and discover that I'm wrong and admit to it. In fact, judging from Banzai's comments, we seem to complement each other well in our different tastes. Also, Banzai, did you see Sig came out with a 716 DMR chambered in 6.5 Creedmoor? Thought you might enjoy that if you hadn't.