I would not recommend buying a shotgun at this time.
I would instead suggest having a seasoned shotgunner first have a sit down discussion about 4 Rules of Safety and how these apply to Shotguns and Shotgun Etiquette.
At the range, this seasoned shotgunner can access you for gun fit, which includes not only how the gun actually fits you stock-wise, also manual of arms, where the controls are, and how various platforms operate, particular nuances of each in ammo preferences, inspection, cleaning, lubing and maintanence.
Other considerations include any physical needs needing addressed, first one is obvious- eye dominance. Some folks are dominant eyed opposite of strong side.
[right handed, left eye dominant for instance].
One may have bad knees, have been thru a injury, surgery, lower back pain, carpel tunnel, Gangelion Cysts, herniated discs, ...etc.
How is the gun to be used and for what? Combo guns, those coming with a shorter and longer barrel, offer versititily for longer barrels for less percieved lead, smoother swing for Trap, Skeet, 5 Stand , Sporting Clays, hunting waterfowl, dove hunting....
Shorter smooth barrels offer Serious Situation use, Turkey, Deer, heavy cover for quail , grouse, wood cock...
After all this had been shared and actual shots fired at pattern board and moving targets and statonary targets while you move...
You are better informed, and know what fits you , for your needs and tasks.
This seasoned shotgunner can assist in new guns, in all this Criteria already figured out, or with a used one, for anything that one needs to know in checking out a used one.
Stock dimensions can be duplicated and again the Seasoned Shotgunner can assist in getting your gun now , more fitted to you, and assist in getting it patterened with loads for tasks for distances.
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At the top of Shotgun Forum, read the Sticky's by Dave McCracken.
Do a search for Dave again and members such as PJR, BozemanMT, kudu, TrapperReady, Will Fennell- for starters in regard to Clay games and hunting.
Defensive use, search under Lee Lapin, Gordon , Jeff White and Dave Mc for starters.
Other members are very good to search under, I cannot list them all, so no offense if I did not mention you.
Shotgunning: The Art and the Science - Bob Brister is a great book to have as well.
I am in the minority most times in suggesting one not buy a shotgun first . I just feel the Software is more important than the Harware.