S&W 1000m 20 gauge

Discussion in 'Smith & Wesson' started by aandabooks, Sep 11, 2010.

  1. aandabooks

    aandabooks G&G Newbie

    Anyone know if another makers' choke tubes will work in this shotgun? I can't seem to find anywhere to buy tubes specifically for this gun. They look very similiar to Remingtons but I don't have any 20s to try.
  2. Hammer Down

    Hammer Down G&G Addict


    Your Smith & Wesson shotgun was made by Howa of Japan early on, and the early ones were a fixed choke system. Then Mossberg Bought the rights to them and they made them with interchangable chokes. I believe all Mossberg Chokes will work in it, but Carlson choke company says these will also work in your gun. I hope this helps, Hammerdown

    Interchanges with Winchester, Mossberg 500 and Browning Invector style threads

  3. aandabooks

    aandabooks G&G Newbie

    Thanks for the info. That will make finding more chokes very easy.

    I have the Mod choke for the 2 3/4" barrel and the 3" barrel that I have is a set mod choke barrel. I would like to get atleast a full choke before I take the gun squirrel hunting.
  4. Hammer Down

    Hammer Down G&G Addict


    I have found for most small Game Hunting a Modified choke works best all around. I have seen a barrel with a Full choke Blow game apart or miss it all together due to way too tight of a shot pattern. Below is some neat information on chokes and what they can do for you, I hope it helps and before I changed anything I would certainly pattern your shotgun with the existing choke it has to see how well it groups for you.

    Keep in mind that just because your gun delivers Modified (or whatever) performance with one load doesn't necessarily mean it will do the same with other loads. Also keep in mind that just because the barrel of a gun or its screw-in choke was marked "Modified" or "Improved Cylinder" at the factory does not mean it will deliver Modified or Improved Cylinder choke performance with all loads.
    Different loads from various manufacturers or even different loads from the same manufacturer can vary in a number of ways and those variations can result in a difference in performance even though choke constriction remains the same. Even though the load you just tested delivered Modified performance, another load might deliver Improved Cylinder performance while the next might perform as if your gun is choked either tighter or looser.
    Chart 2
    Standard Choke Constrictions in Inches
    (From Briley)
    Choke Gauge
    DESIGNATION 10/12/16/20 20/410
    Cylinder .000" .000"
    Light Skeet .003" .003"
    Skeet .005" .005"
    Improved Skeet .007" .007"
    Improved Cylinder .010" .009"
    Light Modified .015" .012"
    Modified .020" .015"
    Improved Modified .025" .018"
    Light Full .030" .021"
    Full .035" .024"
    Extra Full .040" .027"
    Super Full .050" -------

    The same rule also applies to different guns. If you test two seemingly identical shotguns with exactly the same amount of choke constriction in their barrels, one might deliver Improved Cylinder choke performance with Load A while the other gun delivers Modified performance with the same load. Like I said before, the only way you will know for certain how a particular gun and load combination is performing is to spend some time with both at the pattern board.

    One of the great things about screw-in chokes is they give us the option of conveniently and inexpensively trying different constrictions with different loads. If you hunt flooded timber where most shots are taken inside 20 yards, you need the largest pattern your gun will shoot while maintaining adequate pellet density. If that box of shells you recently bought is delivering overly tight patterns for those conditions, just screw out the Modified or Improved Cylinder choke and screw in a Skeet or Cylinder choke.
    Moving to the opposite extreme, if the box of ammo you have is not delivering a dense enough pattern at 30 yards for consistent multiple pellet strikes on mallards, simply replace the Modified choke with Full or perhaps even Extra Full. But be careful when using extremely tight chokes as once the optimum amount of choke is reached for a particular load, a further increase in constriction can actually have a negative effect on pattern quality.

    Chart 3
    Number Of Pellets Per Ounce
    8 585 - - -
    7 1/2 410 - - -
    6 225 316
    5 170 243
    4 135 191
    2 87 125
    1 - - - 103
    BB 50 72
    BBB - - - 61
    T - - - 52
    F - - - 40

    *Pellet counts for bismuth and Tungsten-Matrix shot are about the same for lead

    Choosing chokes for specific hunting conditions is quite important. For shooting where most birds are taken inside 25 yards, Skeet and Improved Cylinder are our most useful chokes. When teamed up with the right load, those two deliver adequate pattern density for shots out to 25 long paces and yet pattern diameter is large enough to make hitting birds that flash by just off the muzzle of your gun quite easy.

    For most of the waterfowling I do Improved Cylinder is the most useful although Modified comes in a very close second. While less useful for all-around use than more open chokes, there are times when Improved Modified is a good choice. As a rule, and depending on the load used, Improved Modified will extend range by five to 10 yards over Modified with some loads and yet at closer ranges it is easier to hit with than Full choke. When hunting with a side-by-side or over-under double, I often use Improved Cylinder in one barrel and Improved Modified in the other. About the only time I ever use chokes tighter than Improved Modified is when pass-shooting at longer ranges.

    Those rules work for most of my guns and me but only pattern testing will determine if they work equally well for you and yours. To determine the maximum effective range of a choke/load combination for wingshooting, start by shooting paper at 20 yards and then back off from the pattern board in five-yard increments, shooting patterns at each range.
    Once you see the percentage of shot inside a 30-inch circle drop below 65 percent you have exceeded the maximum range for that particular combination. While I realize it takes only one pellet through the brain or spine to drop a bird for keeps, I also realize it is possible for all pellets to miss those targets and if that happens multiple pellet strikes will usually deliver enough energy for a clean kill.