This is the next step with our Serial Number Database. It is hard to nail down this kind of stuff, and there is lots of disinformation, but we will have a great resource here. If anyone can provide specific data, or corrections, please do so.
G Serial Number Prefix (1973-77) : Model 500 shotguns with G serial number use a specific magazine tube with a ring system around the external diameter of the magazine tube.
The Persuader line (LE / Civilian) was introduced in 1976 and ran until 1985. The 590 was introduced in 1987 and that's why the 8-shot Persuader with bayonet lug was dropped. The 500ATP8SP had a "special non-gare finish on the metal", in 1981 the 500ATP8SPL was parkerized. The first military contract guns were 500ATP6 in 1979.
.gov contract overruns made 1983.
Mil-Spec 500MILS with 590 Heavy Barrel, metal trigger, made in 1997.
Mil-Spec w/ Pixel Barcode made in 2007-08.
Late 2000s: Introduce two versions of one-piece polymer forend.
Late 2000s: Receiver stamp changed from 500A (C, etc) to 500 12GA.
Safeties over the years, approximate:
- 1970s - plastic checkered / well known to break
- 1970s - steel stepped / holy grail of safeties
- 1980s - plastic stepped / most common by far
- 1990s - aluminum stepped / 590A1
- 2000s - wide plastic stepped / beefed up version of common safety
Barrel Stamps, approximate:
- Pre-1988 : Chamber markings only / small fine print
- 1988-98 : Mossberg Logo + chamber marking
- Post-98 : Chamber markings only / large block print ( 20" 590 still use Logo)
Seems to be tons of changes circa 1990.
- Open new Plant in Maverick County TX
- Introduce Maverick 88
- Introduce 835 Magnum
- Contract for Milspec 590
- Beef up Trigger Assembly
- Use slotted hex stock bolt verse slotted dome bolt
- Anti-Rattle leaf spring in forend
- Utilize 'short' 6 3\4 forend
- Move to Polymer Stocks on Security models
- Drilled Receiver as Old Mossy noted