HD shotgun question

Discussion in 'Mossberg 500 Pump Action' started by wicat3, Feb 7, 2017.

  1. wicat3

    wicat3 .22LR

    Messages:
    22
    Hey everyone,

    I have an older Mossberg 500, mid 70's. I bought it to make a HD shotgun with it to place my H&R as a backup. I had an 18.5 barrel already so I have been using that on the shotugn but I really like the look of the 20" barrel and extended mag tube. I have as it stands a 5+1 mag tube and want to increase to at least 7 round mag tube. Looking at the way the barels fit with the mag tubes I dont see a 7 round mag tube working with the 18.5 barel. Normally I would sell my shotgun and buy a 20"HD shotgun but since I have this shotgun already is there a way to convert it to 7 round magtube or a place to get parts that would be in stock to convert to a 20" set up?
  2. Big Red 97'

    Big Red 97' .410

    Messages:
    41
    You have to replace the 18.5" barrel and standard mag tube with the 20" barrel and 7 round tube. You can buy the whole shebang on eBay for about $150-$200. It comes with the barrel, mag tube and spring. Link below. There are many more that's just the first one I ran across.
    https://www.ebay.com/itm/142269393403


    Sent from my iPhone using Tapatalk
    Rossignol likes this.
  3. John A.

    John A. I'm "THAT" guy Staff Member Global Moderator Forum Moderator

    Messages:
    10,901
    Big Red is correct.

    Only way to increase capacity with a 500 is adding a longer mag tube. Only way to do that is with a longer barrel because of the way the barrel attaches to the front of the mag tube.

    Look at Mossberg's Persuader models. The mag goes all the way to the end of the 20 inch barrel.

    With an 870 or 1300, you can add length to the tube without changing the barrel, but the 500 isn't made that way unfortunately. I think most all of us here wish you could, but that isn't the case.

    I have added extended mag tubes to 2 different Winchester 1300's. One is a 7 round with the 20 inch, and the 28 inch barrel has a 10+1 capacity. 11+1 if I'm using my homemade 2-1/2 inch slugs ;)
    Rossignol likes this.
  4. MikeD

    MikeD I'm Your Huckleberry Staff Member Global Moderator Forum Moderator "Philanthropist"

    Messages:
    10,597
    You can buy a 20" barrel, or cut a longer barrel, for a 590/835 and then replace the 500 magazine tube with one from a 590/835. This will allow you to use extension tubes for the 590/835.

    NOTE: Using a 835 barrel will not allow you to use 3.5 inch shells as you will be limited by the dimensions of the receiver. All 2.75" and 3" rounds are good to go.

    I use 500 barrels on my 835 by doing to opposite swap.
    Rossignol likes this.
  5. wicat3

    wicat3 .22LR

    Messages:
    22
    So can I swap 590 barrel and magazine tube to make my 500 a 590? If not where can I get a 20" barrel? I seem to not be able to find them and when I do it seems they are all choked barrels and not smooth bore like my 18.5 is.
  6. old mossy

    old mossy Global Moderator Staff Member Global Moderator Forum Moderator

    Messages:
    12,295
    Yes you can use the 590 barrels as long as you use the 590 mag tubes.
    MikeD likes this.
  7. Conn 500

    Conn 500 .223

    Messages:
    174
    Keep an eye on Brownell's website and type in Mossberg barrels in the search. I've bought 2 hi-cap 20"/extended tube/mag spring for my 500s for $99 each. They show up on the website at this sale price often, be patient. Last time they ran this sale was about 4 months ago, but it always reappears. Nice barrel, too.
  8. Big Red 97'

    Big Red 97' .410

    Messages:
    41
    The barrel/mag tube I linked on eBay is smooth bore. I believe all of the 20" 500 barrels with the 7 round mag tube are smooth/cylinder bore.


    Sent from my iPhone using Tapatalk

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