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20ga 3-1/2" Mag conversion

Discussion in 'Shotguns' started by Matt304, Nov 13, 2007.

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  1. Matt304

    Matt304 Member

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    I just found out that Hastings makes the 20g 3-1/2" magnum sabot loads. Those sound very interesting to me. Could I simply ream the chamber longer in a Winchester 1300 pump rifled slug gun in 3" to use them? Will the factory barrel/action hold the extra pressure just fine?

    Thanks.
     
  2. ArmedBear

    ArmedBear Member

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    Weird. I don't see a barrel for it listed on Hastings' site. You'd think they'd sell the barrels, and the ammo, right?

    I have no idea about reaming the chamber that much; my instincts say "probably not" but I don't have a Winchester to look at. Barrels tend to be flared towards the chamber, and get thinner as you move towards the muzzle.

    OTOH reaming the forcing cones 1/2" is pretty common.
     
  3. mnrivrat

    mnrivrat Member

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    A pump conversion is very very unlikely .

    The 3 &1/2 inch 12ga. required re-design of the shotguns being used to include a longer receiver and parts to handle the extra length. Even if the barrel on your gun had enough metal to withstand the re-chambering, the action would not allow for the mechanical handling of the longer case.

    They are converting the break open NEF - H&R handi-rifle guns to accept the rifled Hastings barrel with 3&1/2 inch chamber.
     
  4. ArmedBear

    ArmedBear Member

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    That makes sense.

    You're absolutely right: models of receiver guns that handle 3.5" shells are different from similar guns that are set up for 3" or shorter shells (E.g. Beretta 391, Remington 870 and 1187, Mossberg 930/935 and 535/835).
     
  5. 41magsnub

    41magsnub Member

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    Just a related point.. My Model 120 (basically a 1300) 20 ga 3" mag barely cycles a 3" mag shell after it has been fired (they barely fit out the ejection port) and is extremely sensitive to short shucking with them. There is no way it could handle a 3.5".
     
  6. ArmedBear

    ArmedBear Member

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    Oh yeah. The difference in the ejection port is so pronounced, you can see it even in these little pictures (870 Magnum vs. 870 Super Magnum):

    [​IMG]
    [​IMG]

    And that doesn't even get into the differences in the mechanisms to allow for more travel.
     
  7. rcmodel

    rcmodel Member in memoriam

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    Hastings FAQ:

    http://www.hastingsammunition.com/id11.html

    There is no mention of re-chambering any brand or type of repeating .20 ga shotgun for 3 1/2" sabots.

    Only single-shots that are built heavy enough to handle the power & recoil.

    1224.jpg
    rcmodel
     
  8. Matt304

    Matt304 Member

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    I figured it would probably be too long to eject, but I had to ask out of curiousity.

    And for the sake of curiousity, what about this... What if the barrel could hold the pressure; would it be possible to feed one round, eject it mostly, and pull it out if it need help being removed from the port? I know this sounds, well, counter-intuitive and maybe a little odd. But, I honestly only desire one shot, and I would be willing to put up with this to have one shot at a time if it was do-able.
     
  9. Capstick1

    Capstick1 Member

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    I wasn't aware that they made 3.5" 20ga shells. I thought that was only in 10 and 12. This might be a subject for another column but why is it they make a 3.5" 10ga shell but not a 2 3/4" 10ga shell like the 12ga has?
     
  10. Dave McCracken

    Dave McCracken Moderator In Memoriam

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    Capstick, the 3.5" 20 gauge is only a slug gun. See a thread on it I started maybe a month back.

    An older 10 gauge shell was the 2 7/8" load.
     
  11. langenc

    langenc Member

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    Read somewhere that the 3" 20 gauge shotgun was a very poor invention=shot column too long.
     
  12. Orr89rocz

    Orr89rocz Member

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    the new 3.5 inch 20 gauge load surpasses alot of the 12 gauge rounds out there in performance and probly matches the recoil. its a good idea but no guns will be changed to effectively handle those rounds unless its a single shot gun which i dont like
     
  13. ArmedBear

    ArmedBear Member

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    A bit OT because we were talking about slugs, but...

    12 Gauge bore diameter is .73"
    20 is .615"

    So for some reason, a 3" 20 Gauge shell has too long a shot column (probably true), but people think a 3.5" 12 Gauge shell is a great idea, worth extra money for the gun and the shells?

    Think about that one...
     
  14. mikec

    mikec Member

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    At least once Elmer Keith wrote about that.
     
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