HI folks,..
my first post here, but have been a regular visitor in your forums for valuable info on firearms. first of, great forums guys...
maxinquaye - the mossbberg you mentioned (590, 8-rd., syn. stock, ghost ring, bayo-lug) is actually the model 590A1, this particular model has a thicker barrel than the ordinary 500/590, i think having the thicker barrel, is why everyone is saying that, this is mil-spec. I've read from another forum (sorry, forgot where) that you can exchange barrels between 500 and 590 models, with the exception of the 590A1, bec. of it's thicker barrel. got mine for $429, so you got a great deal there, the less than $300 ones are the 500's and 590's, which has a thin barrel.
sorry about my long reply,.. hope this helps.
keep it in the X-ring, and safe shootin'
....jhunnetaz