I actually know little about choke tubes, just the basics.

My A-5 is a fixed choke, i.e. no removable tube.

It's i.d. at the end of the barrel is approx 9/16''.

By BPS has a lot larger tube which is almost 3/4''.

I dunno about the modified tubes, but generally speaking tighter tubes give a smaller pattern real close, but opens up at longer ranges than large tubes.

I've had hunters yell at me for not shooting sooner, then they're in awe when I drop pheasants at longer ranges than they could ever hope for with thier big tubes.

I usually just smile...

 

For Choke tubes you have:

Extra Full like turkey slayer for turkeys good from 45-60 yards.

Full for geese and long range big ducks, ie. sea ducks good from 40-55 yards.

Improved Modified for long range pheasants and medium to long range ducks and small geese good from 35-45 yards.

Modified for pheasants and large grouse at moderate range good from 25-40 yards.

Improved Cylinder for short range pheasants and ducks over decoy and geese over decoy better with bigger shot than M and IM. Good from 20-35 yards.

Cylinder is the bore diameter of your shotgun barrel at the forcing cone, because most newer shotguns are back bored to accept thicker choke tubes.

Skeet is even more generous than cylinder and you may have guessed is for skeet but can be used for ultra close small birds.

Some are designed for lead and or steel and other nontoxic shot.

For 10 guage add 5 yards to the figures.
For 16 guage use the same figures.
For 20 guage subtract 5 yards from the figures.
For 28 guage don't shoot past 30 yards.
For .410 caliber don't shoot past 25 yards.

 

For trap I would recommend a full choke (tight pattern). For Skeet I would open it up a bit.

Wabbits shot with a 22??? Nothing like watching a wabbit (Jack Rabbit) getting nailed with a 270. It's amazing how far the fur flys.

 

I do cowboy action shooting, which is a sport that requires you to use four guns on each stage -- two revolvers, a rifle and a shotgun. The pistol and rifle targets are usually stationary, but at our last match we had to shoot a knockdown target with the rifle. The knockdown was attached to a cable that released a rabbit. You had 5 shots left in the rifle at that point (assuming you had hit the other 4 rifle targets and the knockdown/release target with the first shot) and had to try to hit the rabbit on the run with the remaining 5 shots. If you think taking the rabbit in Sporting Clays is hard, try it with a lever action rifle instead of a shotgun! I only saw two guys out of maybe 50 actually get it, and I wasn't one of 'em.

My main cowboy match shotgun is a classic mule-eared coach gun. It's a side-by-side 12 gauge with 20" cylinder choked barrels and external hammers. Think Doc Holliday in the movie Tombstone. It's big fun for the short range pigeons and flip-the-birds in cowboy matches, but pretty much useless beyond 30 yards or so. For longer range targets, I switch to a classic Winchester model 1897 12 gauge pump with a 32" full choke barrel. It's a lot slower to come on target than by double barrel, but it will really "reach out and touch someone."

 

man i wish i had some cool ranges to go to that weren't a 4 hour trip for me...

I guess I'll just have to train the wife to run the clay thrower for me...that will never happen....