jrfoxx,
You're welcome.
I used to have a 590 SP like yours a few years ago but sold it due to "financial difficulties" at the time...otherwise, I sure would have kept it.
Even with the bead front sight it aimed/hit just where I needed it to. I just would have liked to have rifle type sights in order to "zero" slugs to hit point-of-aim (I cast and load my own slug loads). Can't do that with a bead sight setup...if a bead-sighted shotgun shoots a bit off center, you have to use Kentucky Windage to correct it. I didn't want to do that...my guns MUST shoot/hit where I am aiming.
But at that same time of "financial embarrassment," I decided that when things improved for me $$-wise, I'd replace the 590SP with another one, but probably try to get Ghost Ring sights on it instead of the bead sights mine had had (but at least it WAS Parkerized and had a bayonet lug).
I don't recall even being aware of a 590A1 version at that particular time but I was probably just plain ignorant.
Recently, my "financial difficulties" ended big-time and although I could then (and now) get any guns I wanted -- to replace those I had sold or get any others I had ever wanted -- I didn't WANT to go back to having lots of guns, assorted ammo/calibers, a variety of accessories for each gun, etc., requiring a deuce-and-a-half truck to move...it was way too much "stuff" for me!
I wanted to reduce the number and calibers of guns I would have the rest of my life...sort of downsizing, if you will as I got older, to the most-efficient essentials. I just felt too burdened by all those assorted guns/ammo/accessories and their corresponding reloading bullets/powders/dies and such to keep each one fed.
And, since I planned to move a few times before I finally settle down to stay some place the rest of my life, I wanted to make moving easier by having less stuff in general. That meant getting rid of lots of my stuff, not just keeping the gun-count low!
I still wanted to replace the 590SP I had sold earlier as I see the 590 as the best home-defense shotgun for me, so I "allowed" myself to purchase one since that would be the LAST shotgun I would ever buy, hence no serious increase in the # of guns I'd have and that would be within my plans of having a minimal # of guns in my "arsenal."
Consequently, doing some online research to search out the best source for a 590, I "discovered" the 590A1 and decided to get that one instead of a 590SP. I kept the 500 "Cruiser" for my "car gun" as it was given to me by a friend since I do not sell guns that were given to me by friends, only guns I have bought myself. And with it's two pistol grips, the shorty 500 sure IS a dandy car gun (it lives out there in the car 24/7 with a couple of ammo pouches and a sling).
As for 590s with no bayonet lug, bead front sight, I believe you may be referring to a version of the Mossberg 500, i.e., the Mossberg "Persuader" (not a 590) which even used to be (still is?) sold in WalMarts...don't recall ever seeing a 590 sold there. I also don't recall seeing a 590 with no bayonet lug.
The Persuader is a great choice for someone wanting a home-defense shotgun of increased magazine capacity over the 500 -- like the 590 has -- but who don't need/care about Ghost Ring sights, bayonet lug or a Parkerized finish (since said 500s -- Cruisers and Persuaders -- usually came in blue finish only).
Yes, you're right that the variations of the 500s and 590s can be confusing, and I'm no expert on Mossbergs, so I can't speak on any other versions out there except the ones I have addressed in this thread...sorry.
Big Mac,
Yes, I like the bayonet lug, too, if for no other reason than to annoy anti-gun liberals!
It IS quite usable in a close-quarters situation -- perhaps when being mobbed by Zombies (!) for instance -- but I'm not sure I would have a bayonet actually attached. In a home-defense scenario, I'd have my 590A1 in my hands and my 1911 in my military-issue (M3) shoulder holster for immediate backup duty. And a VERY sharp Moro barong in a sheath.
That should cover the problem(s).
If not, it's just my time to go.
-- John D.