Anschutz knows what its doing for making accurate target and benchrest rifles, and has had many decades to test various designs in the highest level of competition. I believe they are made for 50m distance (?).
They choose long heavy barrels in 26 and 27 inch lengths, and a twist of 420mm (16.5 inches). While the barrel length may have been originally chosen for sight radius for aperture sights, carbon fiber bloop tube technology (with and without tuner weights) is mature, and I find it difficult to believe that Anschutz would continue to make these long barrels if it was a "waste", when the extended bloop tube technology can function for sight radius. The long barrels must be doing something well, better than a 20 inch barrel.
For 50m competition, I would have thought they would offer other benchrest shorter barrel length options if it provided any advantage to winning? They don't offer short barrels in the 20 inch zone other that the silhouette models, which require less absolute precision than for an ISSF score or benchrest group/score target, where 1-2mm can make or break your aggregate groups or score.
Caveat: This is for subsonic target ammo at 50m.
Perhaps there may be a better combo of ammo velocity, bullet weight, and twist rate for rimfire super long range? (e.g. where higher velocity ammo is used?)
Anyways I am open to seeing some experiments, as its always good to experiment with alternatives. Let's see the experimental evidence.
(Aside: In 22LR rimfire, we are constrained by the match chamber lengths. We are stuck with the design of the archaic heeled bullet, that should have been retired in the 1870's, but it wasn't, and we are now stuck with it. There is no room for a longer bullet. My CZ'z and Anschutz rifles engrave target ammo bullets with the bolt close. Neither brand will chamber a CCI Stinger. Maybe if custom chambers were made for for longer heavier bullets, and higher charge weight energies became a thing, we might see some cool results with shorter twists. That would require a revolution in rimfire cartridge design and new rimfire chambers. But then again that is really what centerfire is for, where the heeled bullet was abandoned, and centerfire primers were found to be better than crushing primer in the rim. 22LR rimfire seems to be locked into a very narrow design box without any room for advancement, other than higher manufacturing consistencies for primer, powder, and bullet center of gravity).
