I have my 1911 and my Bushy carbine for home defense. I also have a 870 with a rifled 20" barrel.
My question is I use my 870 for hunting. But what happens if I shoot #4 or 00 buck out of that barrel. 1. what does the pattern look like compared to a smooth-bore? 2. what kind of damage do I do to the rifled barrel? Thanks in advance for the input from everyone.
Shooting shot or buckshot out of a rifled barrel produces REALLY bad patterns, usually "Ring" type patterns in which the shot forms an actual ring-like shape with a large hole in the middle.
Needless to say, this is very ineffective when trying to hit a target.
As for damage, standard lead shot won't harm the rifled barrel, but it WILL lead-up very badly, and will need quite a bit of scrubbing with brushes and solvent to remove it.
Best advice here, is to shop around for a smooth barrel.
You can buy a used, longer barrel and cut it down yourself, buy a new barrel from Remington, or a Remington-type barrel from Mossberg.
The Mossberg barrels for the 870 are fairly cheap.
You can often find short barrels at good prices by asking on the gun forums.