winchester model 70 twist rate

Discussion in 'Technical Questions & Information' started by chim, Dec 20, 2007.

  1. chim

    chim New Member

    Dec 18, 2007
    united kingdom
    Hi guys i have a .223 Winchester model 70 ranger .
    this is my fox gun it has t4 reflex a Bushnell banner on the top
    i have a couple of question
    1, can anyone tell what rate of twist this gun has
    i believe it could 1-9 or 1-12 ?
    2, i have just started loading my own with some success
    can some one tell me the optimum weight of bullet to use
    i shoot a 55 grn boat tail for target shooting
    and a 55grn vmax flat back for hunting
    the powder i use is accurate 2230
    primers seller and bellot winchester shells
    i can get about 2inch group at a hundred yds
    i have used factory ammo about the same

    rgds Tim :eek:
  2. williamd

    williamd New Member

    Mar 21, 2007
    Probably 1:12 but some are 1:9. Run a tight brush on a rod through and you can get pretty close ... close enough to discern 9 or 12. Mark the rod and see how far it goes in for a turn.

  3. chim

    chim New Member

    Dec 18, 2007
    united kingdom
    Hi williamd i have tryed that but it seem to be coming out a 10.5 ?

  4. williamd

    williamd New Member

    Mar 21, 2007
    LOL! Almost averaged them. I can't offer anymore suggestions ... dig into Winchester/Browning website some is all I can suggest ... or take it to a shop/smith who can guage it.
  5. chim

    chim New Member

    Dec 18, 2007
    united kingdom
    back to the top please:eek:
  6. LDBennett

    LDBennett Well-Known Member

    Dec 20, 2003
    Hesperia, CA

    The 55 grain bullets shoot well in anything but the really fast twist guns. Those fast twist barrels (around 8) are typically for the military guns like AR15's. In recent times the Military went to 69 grain bullets from the original 55 grain ones and had to increase the twist to accomodate them. Most commercial guns, like your Model 70, use the slower twist barrels and are best surved by bullets around 55 grains. The match and plinker 52 grain bullets also shoot very well in the slower twist barrels.

    If you have the really fast twist barrel and shoot 55 grain hunting bullets through them they literally disintergrate from the high rotational speeds. This happened to me on my varmitized AR15 style 223 that has a fast twist barrel. The bullet literally missed the 2 foot by 3 foot backer board. Once I started using the bullets from 69 to 75 grains, the accaracy was great with sub one inch groups at 100 yds for five-five shot groups averaged.

    I think any twist barrel from 10 to 14 shoots 55 grainers fine. Its the 7.5 to 8.5 barrel that need the longer heavier bullets. Run some Geenhill calcs on common bullets and I think you'll see that.

  7. LongRifles

    LongRifles New Member

    Hey bud, the "average" you were talking about. . .does this mean you are getting different numbers each time?

    If so, this may work for you.

    First off, cleaning rods are not equal. I like the Dewey rods, but the important thing here is that its one capable of rotating freely under load. That's the part that gets some rods disqualified.

    Anyways, put a jag on it with a patch that's either dry or wet.

    Make a clock position indicator on the rod up by the handle with a piece of masking tape. A "flag" to mark position.

    Insert the rod into the bore ensuring your past the throat and into the bore a little ways. Note the position of the rod and then use a tape measure and take a reading from an arbitrary point on the back of the receiver to a well defined point on the back of the cleaning rod. (Back of the rod, where the rod inserts into the handle, any place will work as long as you know exactly where that point is when you take your second reading.

    Push the rod with nice and even pressure until your "flag" indicates one complete rotation.

    Measure again off of your datum point (the receiver) and the spot you picked out on the back of the rod's handle.

    Jags fit nice and snug ensuring an accurate "trace" of the bore's twist. This is why I like doing it this way.

    One thing to make sure is that the jag is screwed into the rod nice and tight prior to trying any of this. False readings are a sure bet if its not.

    Good luck.
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