There isn't a 220P. There is a 220F, which is bolt action, and a 220B, which is single shot and breaks open. It will state on the barrel if it is 2-3/4" or 3". 3" will fire either. You can load a 3" into a 2-3/4" chamber, but you should not.
Both guns will handle all modern 12 gauge ammo, as long as you stick to the proper length shell if it is 2-3/4"
Next is the choke. It is possible to fire slugs through any choke, but it is not recommended to fire them through anything tighter than Improved cylinder (IC). It should state on the barrel. I expect most are "Mod" (Modified) which is tighter than IC.
how much is a steven's 12ga model 770 shotgun made by savage arms corp worth?
$75-$125 depending on condition.
you may find some info at the savage arms website.This was the maker of your shotgun,savage/stevens.
Those I've seen take 2 3/4 or shorter.
One was purchased new in 1974.
yes they made one, i have and love one, it is a 12ga pump-action with a tang mounted saftey, nice for lefties
12 ga. CHOKE MODEL WH A 45233 Shotgun bore is in excellent condition. Gun barrel and stock somewhat corroded.
Mossberg
$3,000
need a diagram of sears model 66m shotgun for takedown
Whats the valve of a Stevens model95 12ga shotgun
For a couple of years in the late 1980's Savage marketed a combination gun made by Marocchi of Italy which was chambered in 12ga over .222 Remington and 12ga over .308 Winchester. The gun was designated as their Model 389.