Mossberg 500 Barrel ?

[PineyFolks]

Greetings--

I've got a Mossberg 500-A w/ an 18' barrel. I"d like to get a 28" barrel (mod or adjustable choke). I see some around. They all say model 500 barrel.

Is there a difference in barrels for the mod 500 and 500-A ??

[AggieMax]

If I am not mistaken, the 500-A designation is for 12g. For instance, on my Moss 500, it is notated as the 500C for 20g.