the chamber length should be stamped on the barrell just ahead of the reciever, something like "12 gauge for 2 3/4 " or shorter shells or 12 gauge for 3" magnum shells. pbl I own one it's 3''
30"
500 USD
The Savage model 220 was available in 12 gauge,16 gauge,20gauge,28gauge,and 410 gauge chambered barrels,with a barrel length of between 26 inches-32 inches.
If it's a 16 gauge shotgun, the shell length is 2 3/4 inches.
$175 - $200
You will have to provide the model, type of action, barrel length, gauge
6lbs up to 8lbs+ depending on model variation and barrel length.
2400
300-400 USD
try this website: http://www.winchestercollectibles.com/id7.html
Mossberg in the 1970s
the shotgun takes a 2 3/4 shell