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when to mag and when not?

Discussion in 'Shotguns' started by gringolet, May 30, 2005.

  1. gringolet

    gringolet Well-Known Member

    an old 870, in good condition..made in early 60's. will this gun use 3 inch shells or should only 2 3/4 be used regardless of what barrel may be used?
  2. kudu

    kudu Well-Known Member

    The problem lies in the receiver. It is more than likely a standard receiver and not a magnum. Even if the barrel says 3" shells the receiver won't allow them to be removed from the gun once they are fired because the ejection port is too short. It is possible to shoot the magnum shells, but you may have to remove the barrel after the shot to remove the hull.
  3. gringolet

    gringolet Well-Known Member


    thanks, that explains that. 2 3/4 it is.
  4. TrapperReady

    TrapperReady Well-Known Member

    No need to remove the barrel as long as you have a leatherman. Just grab the plastic and yank.
  5. dfariswheel

    dfariswheel Well-Known Member

    A little more info.

    Unless the receiver is marked "MAGNUM", it's a 2 3/4" receiver.

    The receiver can be converted to a 3" gun by having a gunsmith with the special riveting tools replace the shorter ejector assembly with a longer Magnum ejector.

    Other then the longer Magnum ejector assembly, there's no difference between standard and Magnum Remington receivers.

    You would also have to buy a 3" chambered barrel.
  6. Black Majik

    Black Majik Well-Known Member

    Checked the serial number on the receiver. If it ends with a V, then it'll only take 2 3/4" shells. If it ends with a M, then it'll take 2 3/4" or 3" magnum shells.

    If you shoot magnums, you must have a barrel that's chambered for 3" magnums also. (pretty common sense.)
  7. gringolet

    gringolet Well-Known Member


    thanks, looks like this old girl is getting a trip to the gunsmith.
  8. Fred Fuller

    Fred Fuller Moderator Emeritus

    Remington introduced the 870 in a 12 ga. 3" Magnum version in 1955 (the 870 itself was intorduced in 1950). Serial numbers on all the 12 ga. 870 Magnum receivers I am familiar with end in the letter M. If your gun has an M at the end of the serial # and a 3" chambered barrel you're good to go for 3" shells.

    I see no need to get all excited over 3" shells for anything much except waterfowling or maybe turkeys. Softer kicking and less expensive 2.75" loads will handle the vast majority of tasks perfectly well.

  9. Nnobby45

    Nnobby45 Well-Known Member

    3" vs 2 3/4"

    The magnum ejector sits farther back and allows the 3" case to travel reward far enough to clear the chamber before being ejected. With a 2 3/4" ejector, the case hasn't cleared the chamber before the ejector is trying to kick it out. There's no difference in the dimensions of the ejection port--at least not on the 870. The magnum ejector works fine with both standard and 3". :)

    Does anybody know if the 3 1/2" mags work with both 2 3/4" and 3" ammo? Seems there'd be some differences in receiver dimensions on those. Wouldn't a 2 oz. Brenneke slug in 3 1/2" be comforting if one ran into a large carnivore that wanted to eat you for breakfast?! Hate sighting one in, though.:D

    Be advised, for those of you who might be new, that a 3" shell will likely chamber just fine in a 2 3/4" chamber. However, when fired, there isn't enough room to allow the crimp to unfold--pressures skyrocket, with a resulting possible disaster.

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