You can use 2-3/4 inch shells in your 20 gauge shotgun's 3-inch chamber... no problem, it's done all the time. Shells (2-3/4") made for shooting skeet give excellent, even patterns and are not loaded heavily with powder or shot.
However, the shot size is often a bit too small for best use on ducks, pheasants or rabbits (but it will work in a pinch at closer range)... but #7� & #8 shot sizes work quite well on quail, partridge and the lighter-built game birds.
I recommend you simply take the gun to a good gunsmith, tell the gunsmith your (your wife's) needs and see what is possible to do with the gun & barrel you have... and the cost to do it. Most gunsmiths are knowledgable, patient people... and will advise you as to what you might need for the game your wife intends to hunt.
A 28" or even a 30", full-choke barrel is good for trap shooting or pass shooting on ducks... and possibly for shooting wild turkey, but a 26" barrel is more handy for most small game hunting.
I'd recommend a 26" barrel with screw-in choke tubes so that your wife can hunt any game she wants (turkey, duck, pheasant, quail, partridge, etc.) or shoot in any shotgun sport such as sporting clays or skeet.
I'd definitely get the new barrel with a 3-inch chamber. With 3" shells, a 20 gauge can throw a load eqivalent to a standard 12 gauge load. This is one major reasons the 20 gauge has gotten so popular.
I'd specifically ask the gunsmith about just buying a new 26-inch barrel with the abliity to use choke tubes built into the new barrel. Then, depending on what kind of hunting she'll be doing, you will need the 2 most common choke-tubes... the improved cylinder and modified choke tubes. She can use your existing 30-inch, full choke barrel if she does pass shooting on ducks or possibly for hunting turkey. However, if she hunts turkey, she should check into the "super full choke" choke-tube which really concentrates the shot-pattern (for head-shooting wild turkeys).
The strength of the load is stated on the side of the shotgun shell box. Look for the amount of "drams equivalent" of powder used in the load. That is a measure of the amount of powder used in the shotshell load. The "rule" is the higher the "dram equivalent", the heavier the powder charge and the greater the recoil.
This "rule" also applies to the shot load... the greater the weight of the shot load in the shell, the greater the recoil. A heavy shot charge (1� oz.) and a large dram equivalent ='s heavy recoil, but the action in the Remington 1100 will "soak up" about 1/3rd. of the recoil.
The Remington 1100 is one of the very best semi-automatic shotguns you could buy at a reasonable price. Many others are more expensive, but not really any better for your purposes.
Good luck... <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />
Strength & Honor...
Ron T.
