Canned Heat,
The test your referring to is not comparible to the rifle I just built. The main reason is because in Dans article, the barrel is a tapered barrel, this one is not. At 28" from the breech face, that barrel is already 0.250" smaller in diameter then the one on this rifle. At 45", that barrel is a full 0.500" smaller in diameter. The two can not even remotely be compared as having similiar rigidity.
Also, I am sure Dan would be the first to tell you that very long barrels can be extremely accurate. Consistancy as far as accurate groups is simply a matter of finding a load that produces a consistant barrel vibration pattern so that the muzzle is at the same location every time a bullet leaves the muzzle. It really does not matter how much the barrel vibrates as long as its a consistant vibration pattern and the muzzle is in the same location when the bullet clears the brake.
I respect Dan as much as anyone in the industry, thats why I use nearly 100 of his barrels every year.
Also, you need to find some studies on the effect of the weight of a muzzle brake or suppressor and its effects on dampening barrel vibration. Simply put, it has been proven many times that a substantial amount of weight located farther out from the muzzle will have a positive effect on accuracy potential.
As far as your comments about the AR-50 compared to the McMillan. The AR-50 is sold as a complete rifle. The McMillan is sold mainly as a custom receiver which has to be built into a rifle. The McMillan is for the most part a custom receiver and is made to match grade specs right out of the box, or at least its supposed to.
For a good comparision, think of the AR-50 as a Rem 700 and think of the McMillan as say a, well, custom McMillan receiver.
Out of the box, the Rem 700 is a very good receiver but for a precision rifle it needs certain things done to it to perform this task. As does the AR-50 receiver. There are not many shops out there doing this. Most look at a $3000 rifle and never consider tearing it apart just to rebuild it. That is why you do not see all that many custom rifles based on it.
That said, if you look at the rifles used in the FCSA 1000 yard BR matches, especially the Hunter class, the AR-50 is very popular, yes because its an affordable rifle compared to a full custom 50 BMG.
Another bonus of the AR-50 is its design, is that you CAN true it and accurize it just like a Rem 700.
The McMillan is no stiffer then the AR receiver by any means. ITs more popular because there are alot of top end shooters using it and McMillan offers several stocks for it. With the AR, you have one stock choice and its not "pretty" and its not the best for true BR work but its stable and it works but its not "pretty".
I fully understand your trying to understand this stuff but you also need to learn that if your going to get much out of what you read, you have to be able to objectively look at a study and see if its applicable to something else your reading about.
You also need to realize that just because something is not in the "IN" or used by the masses, that does not mean there is something wrong with it.
You seem to be a very educated person, at least from the way you talk, that is either the case or your trying to come off that way. I personally believe the former but if your really trying to learn, open your mind and see all the different points of view and you will learn much more.
If this rifle had a tapered barrel that was only 1.250" at the muzzle, I would agree with you, there would be some severe barrel whipping but that is not the case, there is alot more steel in this 30 lb barrel then in the one in the article you read.
You need to also realize that there was no where in that article where Dan ever said that a very long barrel can not be extremely accurate. Do not read more into an article then is written and don't over think things.
Good Shooting