The additional 2" of barrel may assist the shooter in swinging the barrel to follow the bird when shooting. Originally, the additional 2" would ensure that all of the black powder would have the chance to burn, increasing the range of the shot. This is no longer a consideration with smokeless powders.
The Remington Model 10 slide action has barrel lengths of 26" 28" 30" and 32"
50-500 usd
The barrel on my 67 series D is 28 in.
50-500 USD depending on specifics
Probably.
It depends on what your after. For ruffed grouse I would chose a 26 or 28 inch barrel. For pheasant I would use one with a 30 inch barrel. It all depends on what you hunt and how far out you want to touch. Then that will take you into what chokes you want for the gun you'll be using.
100-2000 usd
No
find a replacement barrel and cut to the length you want
26
28 is bigger. .550 vs .410
To determine the exact value of a Pietro Berretta double barrel shotgun a number of factors would actually need to be taken into consideration. Most importantly, the condition of the shotgun.