Are shorter barrels more accurate?

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sorry, but thats a different circumstance than I was talking about, i said front to back, that is all about side to side or up and down, I said only in certain situations, granted if takes some bad tolerances for it to happen....and it is the same reason why we bed out actions and barrels in our stocks of our bolt rifles....and the same issue, front to back, thats why we have a sequence and torque specs of tightening our action screws on our bolt guns, there is a reason it changes accuracy, and drastically in some cases

believe me, i can make your upper and lower receiver fit affect your accuracy....

I don't think you understand what I am getting at, if you took the same exact setup each time you shoot, it would not affect accuracy, the problem comes in to how you torque the gun, if you can eliminate the slop between the upper and lower receiver, it will make you more consistent in your hold or rest, less torque. It makes it consistent each time. Only the front to rear slop would affect accurace, but the good part is that the tolerances on the takedown pins and holes are very good and I have not seen slop there in a long time.

Think about when you go to the range and what rest you use. I use either a lead sled or a hart front rest with rabbit ear rear. How do you hold your gun? How do you cradle the rear of the stock? Do you make sure that your gun sits perfectly in the front rest after each shot? The more inconsistencies you can eliminate, the more consistent you will be.

Well again (FWIW): Per the link I posted above--"The fact is that the bullet exits the bore before movement of the receivers produces a measurable effect."

Regardless of what the shooter does the relationship of the optic/sights to the barrel will not change, and the projectile will have left the bore before the upper moves in any significant way with relation to the lower housing. All I can say is that it has been tested multiple times and no measurable difference in accuracy has ever been detected.

As far as Shooter consistency with relation to position goes, I'd say your lower would pretty much have to be falling off of your upper to affect your position in any measurable way. I hope I don't sound like I'm coming across as an argumentative jerk in the way I'm saying this, it's just that this is the way I've always been taught, and it bears 100% in agreement with everything I have ever observed in the real world as well. I know it sounds counterintuitive (as was noted by Armalite), and that is why this discussion seems to pop up in the AR world a lot. It's just that no reliable source has ever demonstrated a centilla of difference between tight and loose lowers. It has certainly made the makers of the Accuwedge happy though. Kinda like full length guide rods on 1911's, butt plugs on Glocks, and "anti-walk" pin sets on ARs. That is my strongly held opinion at least, and I'm sure not everyone will agree.