Took out the brand new 590A1 with ghost rings up on the mountain to shoot just a few minutes ago, tried some slugs i had at about 35yds, and they were hitting about 12" low.  I fired some 00 buck as well, and it seemed to be centered in the same area.  I also had some bird shot, it seemed to shoot low, but not quite as low as the rest.  I tried adjusting my rear ghost ring, but I couldn't remember which way it needed, so I just adjusted and aimed way over my target.  Anyone want to help me out??  I fool mostly with old mil-surps, so you'd think I could figure it out, but I've never messed with sites on a shotgun...

Other than the whole shooting about a foot low, the thing ran like a champ, and with my extra limbsaver pad, it makes even those heavy loads bearable

Mine put shot exactly where I aim, only slugs hit low. I did have to adjust the rear sight to get there though.

So I studied the book, and it appears I need to raise my rear site, since I'm shooting low.  Book said to move the site where I want it to go, so it needs to go up.

Shooting Low-rear sight up or front site down

So you found a 590a1? Cool! Weren't you the one that crate a thread about the difficulty in finding one as they were never at your gun shop?

Yeah, that was me.  I ended up driving to cabelas on saturday and picking one up.  I had a coupon to use, so that helped out.