Twist 1/9 and 1/7

Discussion in 'AR-15 Discussion' started by tenntyrant, Jan 8, 2012.

  1. tenntyrant

    tenntyrant New Member

    235
    0
    0
    I had a 1/9 twist on the at I sold my dad and now I have 1/7 twist on my colt, my question is I have a lot of 55 grain 223 and 5.56 will that soot just as good in my colt 1/7 as it did in my 1/9?
     
  2. Chandler51

    Chandler51 New Member

    2,182
    0
    0
    I have a 1:7 in my LWRCI...shoot 55 all the time with no issues. As far as just as good, what does that mean? I think the 1:7 is meant for the heavier bullets, since by virtue of being heavier they are also longer. And I will admit, mine seems more accurate at distances of 300m or more with a 62 grain. That could be because my ACOG is specifically for a 62 grain, and that is what I used to zero. Somebody will be along shortly that will know more than me, I'm sure...
     

  3. Rick1967

    Rick1967 Well-Known Member

    4,991
    47
    48
    I have a 1 in 7 on my AR. I shoot 55 grain for plinking at the range. I have heard people say that a 55 grain bullet can come apart at the rate of spin. I have not seen it happen myself. Maybe it is true, maybe not. But mine shoots just fine. Keep in mind I use a 70 grain bullet for longer distances. I have no idea what that 55 grain bullet would do at say 300 yards.
     
  4. mjkeat

    mjkeat New Member

    4,026
    0
    0
    I have never heard of 55 coming apart in a 1:7.

    I don't believe you'll see much difference b/w the two w/ 55. You're better off w/ the 1:7 Colt.
     
  5. Sniper03

    Sniper03 Supporting Member Supporter

    7,667
    66
    48
    Tyrant,

    The 55s will shoot just fine! But you probably will not be able to get quite as tight group from the 1:7 compared to the 1:9. The reason is the 1:7 was designed to stabilize heavier bullets better so it must have a faster twist rate. But to be truthful about the group you would only realize it if you were to bench and sandbag both rifles and compare the group side by side. The 55s should give you under a 2.5-3" group at 100 yards from the 1:7. Compared to a good rifle with 1:9 should be able to group 1/2 to 1 1/2". Bottom line if you shoot a 5.56 for defense, who cares if you shoot at the target and hit an 1 1/2 high or 1 1/2" low making an actual spread of 3"s.

    03
     
  6. firedawg60

    firedawg60 New Member

    365
    0
    0
  7. Quentin

    Quentin New Member

    7,551
    1
    0
    It should do fine in your Colt but don't expect great performance if you go lower than 55gr.
     
  8. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

    11,380
    1
    0
    Most 55 gr bullets have decent jacket thickness and shoot fine in the fast twist guns. The 52's or lighter tend to have thinner match/varmint jackets and WILL spin apart out of a fast twist gun if loaded to full velocity.