Claymore, An O/U is an excellent choice for skeet or trap ... plus it is a popular hunting gun too. The screw-in chokes pretty much eliminate the need for multiple guns because you can use the choke best suited for your application. For skeet, an Improved Cylinder or "skeet choke" is best whereas for trap, most shooters use a full choke or a Modified choke for sporting clays. Chokes for hunting will depend on the shot size, shooting distance, and of course the size of the birds. After you get 10 posts, you can download a document from the Forum Library titled "Shotgun Chokes and Related Issues". It has a lot of information concerning chokes, shot size, shooting distance, and barrel length. Here's a link: http://rugerforum.net/library/83808-...ed-issues.html
Consider this .... an O/U with 28" barrels is about 4" shorter than a pump or semi-auto with a 28" barrel. This means an O/U will "swing" fast to acquire the target ... much faster than an equal barrel length on a pump or semi.
In years past .... before screw-in chokes and 3" (or 3 1/2") magnum chambers, barrel length was important. A 28" barrel has been the standard for a hunting shotgun for more than a century. Duck hunters often used 30" or even 32" barrels for geese mostly because 2 3/4" shells just didn't have enough range in a shorter barrel. Much of the "long barrel" concept was nothing more than marketing hype ... not a real advantage at longer distances. Longer barrels do two things ... they increase velocity a little and allow a longer choke transition. With older shotguns with "fixed" full choke barrels, it is quite common to see the choke start 6~8" before the muzzle. With today's screw-in chokes, the choking process to collimate the shot in the proper sized pattern happens in the last 2~3" from the muzzle. Of course the older shotguns do pattern much more uniform, but the size of a full choke conventional barrel pattern and a screw-in full choke pattern will be the same. Traditional skeet guns have 26" barrels and trap guns had at least 28" or even 30" barrels.
The newer shotguns typically have a 10~20 yard advantage over the older pre-magnum shotguns. When you couple screw-in chokes and the ability to shoot 2 3/4" or 3" magnum shells, it makes a modern O/U very versatile yet easy to "swing". Advancements in powders and one piece plastic wads have virtually eliminated the need for longer barrels.
My preference for an O/U is 26" barrels but 28" are much easier to find and are better for hunting and trap, whereas the 26" barrels are better for skeet. If you turn into a hard core skeet shooter, chances are you will buy a dedicated skeet gun with conventional (not screw-in) Imp Cyl chokes and 26" barrels.