Well I'm glad you had a few choices that were pretty decent. I wish you would have mentioned that to begin with :wink: . I think most of us were thinking there was something wrong with gun, or you were having target panic problems.
I would pick the slugs that gave you the best groups and go back and try again. Just remember to take your time and go easy. Make sure you let the barrel have time to cool as well. As far as recoil, it can be managed, especially from a bench. Get a better recoil pad for starters. They make replacement ones and slip on ones. They also make shooting clothes with them built in, but you could just put something between the gun and your shoulder if you really wanted. Also adding weight to the gun helps. The even make recoil reducers that go in the stock. And if worst comes to worst get the barrel ported. It makes it louder, but it works pretty well. My mossberg was ported and I liked it. It wasn't as loud as a high powered rifle with a break or anything. A heavier rest helps some too.
Another thing is to not fight the recoil. Especially if you are little. Just let your body roll with the recoil when you fire, don't push into the butt and try to hold it there. Stay relaxed and let the gun move you. This is why drunk people tend to get hurt less in accidents, they are more relaxed. I am a little guy (120 lbs/63 inches) and I don't have a problem with most rifles or shotguns including 3 1/2 inch turkey loads. If you think your auto with 2 3/4 inch slugs kicks, try a light pump with a full turkey load! Darn near nocks me down when I pull the trigger. However if you do it right it doesn't hurt that bad. And good aftermarket recoil pads really do work, they are much better than the stock ones on most rifles.
Also having a gun that fits you helps as well. If this shotgun is just too much for you and it doesn't fit you will you might consider trading it for a 20 ga in something that fits you better. It makes a big difference trust me.
My muzzle loader with 100 grns of powder and a 350 bullet kicks about as hard as my slug gun does. They are both fairly heavy guns though.
You don't have to shoot your gun to test loads either. If you get tired, sore or just can't hold steady con some big strapping guy into helping you out :wink: . Guys are gullable like that. You really only need to shoot it for the final sight in. Checking the gun for groups anyone can do for you as long as they shoot well enough. Just make sure the sights are set for you when you are done.
Good luck and let us know how it turns out. I wouldn't expect stellar results with red dot at longer distances, but it should be Minute Of Deer :-) . I would be happy with 5 inch groups at 100 yards with non magnified sights. If you can get them smaller even better yet. Most that talk about really good groups with a slug gun are using at least a 4X scope and have some bench experience.
Are you the same doegirl from Eders? If so, Hi, nice to hear from you again and see you on other sites.
Paul