Shorter or longer barrels for accuracy? .177,.20 or 22 better for accuracy?

Length doesn't matter... depending on power or if you use iron sights. Shorter barrels can have shorter lock time which can make it EASIER to be accurate but longer barrels of heavier profile give weight to the muzzle which helps dampen movement. It can be difficult to generalize which is actually better as there are good examples in about every configuration. I tend to prefer longer but I know Mike N of Thomas rifle fame tends to prefer more compact arrangements and his success is really hard to argue with.

177 vs 22 again comes down to power more than anything else for target shooting. Higher power TENDS to blow less in the wind but if there's a limit on power, 177 can be better. General accuracy is probably equal within each calibers preferred power. 20 CAN be just as good but there are very few 20 cal pellets to choose from.

I shoot my 22 the most right now but really enjoy shooting the 177s more as they are less noisy and cheaper for ammo.

Just my $.02

Bob

That 18" Lothar Walther barreled AF Talon sounds good enough to me for 25 meter bench rest. Set power level at around 860 to 880 feet per second regardless of what pellet weight you choose to shoot. Tends to be the typical sweet spot in velocity shooting Diablo (normal pellets with skirts) pellets.

Generally speaking longer barrels shoot more accurately at longer ranges, hence the rifle or long gun vs a pistol. Also in general the heavier projectiles buck the wind better so it go's to say larger calibers shoot more accurately at longer distances. At 10 meters I believe 177 is king. 

I doubt locktime has much influence in bench shooting, but even so, barrel length does not Influence locktime at all.

Barrel quality is much more important (including bore polishing, throat, and crown).

Barrel length doesn't matter. Accuracy is going to come down to a combination of pellet fit and a good clean crown. The Air Force isn't going to be the best platform for this endevor, but it will get you started. The flex in the Air Force guns make them hold sensitive like a springer. You generally want the biggest caliber allowed when shooting paper target matches because if you cut a line you get the better score.

Barrel length influences the speed of the projectile you are shooting . The longer the air behind your pellet or slug has time to give acceleration the faster the ammo will fly out of the barrel ( there is a certain limit to this but that is not relevant as no such long barrels are being made) . This means that longer barrels tend to be more used with heavier ammunition as short barrels cannot get them to the desired speed. With lower weight ammunition it also means that you can shoot at lower regs settings with longer barrels getting the same speeds as with higher regs settings with shorter barrels. Hence more economical air usage. ( apart from the fact that rifles with longer barrels tend to have larger airtubes )

manoevrebility and personal preference Related to accuracy is the rest of the story.......

Longer is not better if longer is over 16" and under 20",my experience.fat shorter quality is hard to beat.

I would ask this,what cal.do you want to use,what power level do you need for the distance you are shooting,what pellet do others seem to gravitate to....then see what barrel length ,etc they are using,,,some barrels are set up,made for certain pellets....

I love .20,hands down a great pellet....problem is it is sometimes harder to get pellets for it...I have no problems,a great choice.

I like Redheads to....I have big fingers so it is more of a chore for me to handle little pencil neck .177 pellets.I always take .22 over them when I can .

Thus ,another reason for the .20 caliber pellets.

.177 is very popular and has many different weight pellets and is the go to pellet for many accuracy shootesr...Um maybe I have confused the issue.....

No doubt for me .20 cal. in a 16"-20 " barrel.