Depending on condition, $75-$125. These were "utility" grade guns, and inexpensive when new. Not bad guns, just not a lot of collector demand for them.
Either a full choke,or extra full choke shotgun barrel.
Most ARE shot from full choke- or even Extra Full Choke.
100-300 USD
That will depend on whether the choke tube is rated for steel shot or not.
25-100 USD
$50-$75 retail.
50-300 usd
That will depend on whether the choke tube is rated for steel shot or not.
Either modified or full choke... full choke keeps the shot in a tighter bunch, so it is better for a longer shot.
You can use steel shot with a choke anywhere from cylinder to modified, i wouldn't recommend using steel with a improved modified or a full choke.
How much the shot is constricted as it leaves the barrel.
The TIGHTEST choke (which is smallest) is the Extra Full. The largest (no choke at all) is known as a cylinder bore.