Took the 590 to the range.
9 pellet 00 buckshot had a 8" pattern at 10 yards. That was a lot wider than I expected given what I read in this thread about shot not spreading much. Even at 5 yards, that comes out to a 4" spread. (20" 12ga)
What shocked me more was the #8 shot that I got 60 rounds of because it was the cheapest at the shop ($3 per 20). The first shot I fired, at maybe 5-7 yards, I pulled the target back, noticing the one big hole, maybe 1" in diameter. From what I'd read here, that's about what I expected it to do. One big hole. Then I noticed the entire (8.5"x11") target was completely covered with tiny holes. Looking at the cardboard backer, I noticed the pattern was maybe 2 feed wide. Definately at least a foot and a half.
I am ashamed to say that was the first day I ever fired shot out of my shotgun. It was the first gun I got, and I've spent a good bit of time at various ranges. I fired maybe half a dozen slugs through it one day I went to an ourdoor range that didn't allow multiple projectile ammunition. But I never got around to beginning to put a good number of rounds through the thing until I looked for the cheapest 12ga ammo I could find. I'm not sure off the top of my head what Remington Express 12 pellet 12ga 00 buckshot costs, but it was way too close to a buck a round for my taste in target ammo prices.
So that $3 on a 20 round box of #8 12ga shot was probably some of the best $3 I've spent. Still have a couple more boxes, and I'm sure it won't be the last. And it was FUN. Blew a target through the cardboard backer.
I was also concerned about hitting other people's targets in lanes next to me, given the amount of spread I noticed. But they were friendly, and I said if they noticed me hitting their targets at all, let me know, and I checked later, and there were no #8 shot holes in their backers. So I'll definately be doing this again.
Oh, I did fire a couple rounds of the 00 buckshot I keep in my shotgun. It kicked, but was definately manageable.
So I'd like to repeat what I'm sure has been said here many times: Take the thing to the range !!