I have the Varmint, not the MTR. Still just a 20" tho, and Im dead set on 26" so Ill see if a manu would do it. Worse come to I might take 24" but id rather not. I can do 400 as is now, capability isnt the question for me, I just want better.
From what some hard core addicts have told me its a correlation between barrel mass to mitigate the amount of vibrations produced when firing and the amount of force those vibrations put on the projectile while its traveling down the barrel and when it leaves the muzzle in the air. The CZ is less than 1" in diameter while i think the Anschutz is more along the lines of 1.25" so the CZ will never be on par in that aspect.
As for the barrel length I'm told its a matter of stability and revolutions of spin it puts on the projectile while the length inside of the bore is longer it gives the powders burning off more time and space to remain more consistent in its burn off making your results down range more consistent as well.
Im FAR from an expert, more so over with rimfire as 90% of my shooting has been with a 338, but based on science, and logic I say it makes sense to me.
All barrels will vibrate, even heavy barrels. The stiffer the barrel, the less it will vibrate at the muzzle, but it will still vibrate. Often a beefier barrel is less ammo sensitive. A rimfire barrel tuner can be used to modify the vibrations in a rimfire barrel to improve accuracy.
Regarding Anschutz barrels, the heaviest is 24mm (.945") in diameter and 690mm (about 27.25") in length. These are on the xx13 match rifles, all single shot. The heaviest barrel Anschutz has currently has on a repeater is the 64 action MPR, which has a muzzle diameter of 24mm. (I seem to recall there's a muzzle swell on this model and so the rest of the barrel may be a little less than 24mm.) The 64 MPR barrel is 650mm (25.5") in length.
The additional weight of a long and heavy barrel will potentially provide greater stability because of greater inertia. But the length of the barrel has little to do with accuracy, whether its at 50 yards, 100, or 200 or more.
The most important factor is the ammo. Once the bullets leave the muzzle, they have no idea how long the barrel was that they passed through. The spin the same out of a 16" barrel or a 26" barrel. If the ammo shoots accurately at 50 or 100 yards, it has the potential to be accurate at longer ranges. If it doesn't shoot accurately at 50 or 100, it can't get any better the further it travels. In other words, the ammo that shoots best at 100 will always have an advantage over any ammo that shoots less well.
When shooting at longer distances, even in a very accurate rifle the ES of the ammo used and changes in wind will have the greatest impact on accuracy. Standard velocity match ammo is always better than high velocity ammo. With SV ammo, each 10 fps difference in MV results in .25" of vertical spread at 100 yards, 1" at 200, about 2" at 300, and 4" at 400 yards. Its well worth noting that a box of good match ammo can often have an ES of 30 fps, more if it's an average box of match ammo. This means at 400 yards a shooter who executes his shots perfectly in a perfect rifle should expect at least 12" of vertical spread because of ammo variation alone. Add wind to the equation, a barely noticeable difference of 1 mph of crosswind between shots will move a SV round 1.35" at 200 yards, nearly 3" at 300, and very close to 5" at 400 yards. Gusting winds will make accuracy at long distances very difficult, especially when ammo variation also plays a key factor.
All this is unaffected by the length of the barrel. In the end, there's no reason why a 20" barrel can't shoot as well as a 26" barrel. By itself, the length of the barrel doesn't give additional accuracy. A longer barrel is usually more responsive to improvements in accuracy by use of a rimfire barrel tuner. But even a tuner will not do much if the ammo is not relatively consistent to begin with.
