May sound like a stupid question, but is there any mechnical reason why it should be more accurate then, say, an AK-47?
The reason quoted most often is "tighter tolerances". But as far as I can see, all that would effect accuracy is chamber dimentions, good headspacing, and a good barrel. And, of course, the trigger mechanism. In fact, dropping a hammer on a pin seems to me to be worse for accuracy then, say, have a spring driven firing pin like on a bolt action. Does the hammer falling put a lot of momentum in the lower reciver, thereby moving the POA? This would happen at about the same time the pin hit the primer, wouldn't it?

Anyway, I believe that the AR-15 IS more accurate then many other rifles. I just don't see why it should be that way.

Oh, and by "accuracy" I mean the MOA out of box. From what I've read, the AR-15 is good for 1-1.5 moa out of the box, where as other rifles are (supposidly) worse. I know that the flatter trajectory makes it more shooter friendly, but that doesn't really effect the mechnical accuracy of the rifle.

Oh, i own a standard Bushmaster A1 with a 20" barrel, and I love it ;)

No extra body motions created by involutary flinches created by heavy recoil from a 300Mag or .270 or 30-06.

Once I got over the recoil I shoot the 300mag just as well as the LTR .223.....

We are human....we will flinch or tighten if we think it's gonna hurt.

[:D]

Yes there are reasons...

First off there is very little infuencing the barrel.  If you're not holding it by the handguard (say on the magazine well) its effectively free floated.

The gas system is pinned at one end and the other is free to move (thus not interfering with the accuraccy).  The gas systems of most rifle are fixed at both ends - with a moving mass in them - which effects the barrel.

Of course the tight tolorances (with the multi lugged bolt) help.

Plus, it has no wood stock to 'swell' and push on the barrel differently under various  climatic conditions.

So mechanically there are differences - some of them can be addressed in other rifles (like the tolorances & synthetic stock).

Also worthy of note is the fact that quality .223 ammo is inherently flatter shooting and more accurate than 7.62x39. Also, most AK barrels are not as high in quality as the average US made AR barrel.

Keep in mind though, for combat use 2-3 MOA is at least sufficient unless you're a sniper. The AK series has been very combat effective!

An AR is acurate, well I'll be......I just thought it was throwing lot's of ammo down range![:D]

The 7.62X39 has too large a bullet for the charge and drops like a rock 300 meters out.  The small round of the 5.56 coupled with a 2,700 to 3,300 ft/sec muzzle velocity makes for a really flat trajectory.  Even with a A1 M16, I could routinely hit a half target at 450 meters.

Combine that flat trajectory with lot's of ammo down range and you have one fine weapon.

From here to the wall, the AK is a fine weapon but then so is a shotgun.

The reason the AR is accurate is simple and straight forward:  The bolt locks directly into the barrel via the barrel extension and therefore, headspace is always constant - the lock-up is always the same.  

Most rifles have the bolt lock-up to the receiver, hence the need for a heavy receiver made of steel for example.  With the AR the idea was to use light-weight modern materials hence have the bolt/barrel lock-up.  The side effect was accuracy.  

Don't forget quality. If a top of the line company were to put the same care into QA as the top of the line AR compaines did you would have a much different rifle.

all the above.  the ar system uses no op rod with a wiggling linkage, multiple lugs locking into the barrel itself eliminating the torque or flex of a receiver in firing, a flat shooting cartridge made (generally) to high specs, and guys who reload with an eye towards wringing all the inherent accuracy out of the rifle.  the low recoil and straight line construction from muzzle to shooters shoulder, coupled with a well positioned pistol grip aid in making a stable presentation each time you fire it.  the ar's have some of thte best human engineering of all the modern weapons currently in use.  yeah, the direct impingement gas system is a dirty one by modern, smokeless powder standards but the ar is also easy to take down and clean as a trade off.  also quality control as a milspec rifle.  no one else is consistent as our firearms industries, overall.