There are different chokes that do different things. Most of which do a fair job of constriction for a decent enough pattern. Then some guns are back bored which helps prevent blown patterns. Then there is the "stripping" chokes such as Pattern Master which strips the wad away from the pellets. Supposedly making for a shorter shot string, so more pellets hitting the bird and which mostly are very tight patterns too.
DD, myself, I certainly would not use a Full choke with steel shot, especially a coarser pellets like BB. And this is on modern (meaning in the last 10 years) of American made guns. The reason why American is this--these High Velocity steel loads are an American thing mostly, thus the American gun manufacturers are making their guns much more beefed up to handle the much higher breach and barrel pressures of the HV steel loads. A old "lead" Full choke with a HV coarse steel load can bulge the barrel even on 20 YO American made guns, and the foreign guns like those in Spain or Italy are much softer steel, even today(older foreign guns are even softer yet and no steel shot should be used ever). So these should not be using the US steel shotshell loads IMO with is based on what I have read about the experts opinions.
Also the coarser the pellets, the tighter the pattern. Meaning a Modified choke may shoot a 68% pattern of 4 shot, but a 76% pattern with a BBB, in the same 3", and wieght of peelests, and amount of powder. This is something that it appears that many waterfowlers do not fully understand, but should be factored in when chosing chokes, shotshells, etc..
The Audacity of Bull Crap.
"Typical: Gun-loving, bitter bible-thumping white person" Barack Obama.
Hey I resemble that comment!!! Those are FIGHTING WORDS!!!