barrel length

[ds1]

I think Dave has this one nailed - for practical purposes short is good so 16" over 20" on a .22 RF

 

For the benefit of Harry I would add that in .22 Bench Rest often barrels are longer and thinner than rules require to make better use of the benefits of a tuner - the idea of a tuner to make a "stopped" barrel at the time bullet exits the muzzle - this in conjunction with barrel "ringing" to determines exact length and are good ways to get the most accuracy from a .22 - if that was as clear as mud then one needs to read more Calfee - who is the .22 god of all things rimmfire.

 

As a couple of side points Bill Calfee was able to get reasonable accuracy with a rimmy barrel of about one inch length and that was not my usual crap spelling errata.

 

Second side point with full bore shorter barrels (like the 10.5" one on my poodle shooter) - are just as accurate as longer barrels, potentially more so as a say 12" barrel has more chance of being perfect from end to end than a 24" barrel. The but comes with increased muzzle pressure and reduced velocity for full bore. With rimmy barrels a short barrel as Dave pointed out increases velocity (less drag on the lead slug) and muzzle pressure increase is moot.

 

 

David.