Bullet weight question 223 1:9 twist

Discussion in 'The Ammo & Reloading Forum' started by springerbuster, Apr 2, 2011.

  1. I have a Bushmaster carbon 15 with a 14 1/2" barrel that has a 1:9 twist rate. I am not happy with the accuracy I am getting from 55gr bullets. So far this is the only bullet weight that I have shot through it, some reloads and some factory ammo. I am just wondering if I would have better luck with a heavier bullet. Sorry this may be a question that belongs on another thread. Any help would be appreciated.
  2. steve4102

    steve4102 Former Guest

    Jan 27, 2006
    Lets talk reloads (handloads). What 55gr bullet/bullets have you tried? The better the bullet the better the accuracy. Cheap bullets are cheap for a reason and they usually do not produce the best accuracy.

    Speaking of accuracy, what exactly do you mean by "unhappy" as it relates to group size and target distance?

    IMO the bullet is the number one accuracy component in a handload. That said, powder plays a huge roll as well, what are some of the powders and charge weights you have tried so far?

    I have a 1-9 twist Colt that shoots 50-69gr bullets well, 69 being the heaviest(longest).

  3. muddober

    muddober Active Member

    Sep 19, 2008
    Carson City Nevada
    With that fast a twist you would in my opinion be better off shooting 60 grain plus weight bullets.

  4. retired grunt

    retired grunt New Member

    Mar 30, 2009
    Northern NY
    My bushmaster delivers better accuracy with heavier bullets, try some 69 grain rounds.
  5. jack404

    jack404 Former Guest

    Jan 11, 2010
    heavier is better down under too ;)
  6. Thanks for your replies. The recipe I have been using is 24gr of AA2230c with a Hornady 55gr fmjbt or 55gr Vmax bullet. I should add that I have an Eotech red dot sight on my gun as well. I have a range at my house that is 80 yds and I have been getting about 3" groups at that distance. So another question. Could my problem be the red dot scope?
  7. jack404

    jack404 Former Guest

    Jan 11, 2010
    red dot is not a accurate grouping sight by any means , i have them myself , i like em, but i wont try to qualify for a competition with one unless its a fast shoot ( close in , mobile targets )
  8. American Leader

    American Leader Well-Known Member

    Mar 1, 2011
    I thought the 1:9 twist was stardard on .223? Also, regarding 55 grain bullets, you boy's seen my grouping when I loaded my new Rem 700 VTR with Rem. 55 gr. HP & 27.5C varget, about 3/4" group to start. There was a big difference between 25.5, 26.5, and the 27.5C loads. However, the VTR has a 22" barrel length. Springerbuster may have to find his guns sweet spot?
  9. bmg50doorgunner

    bmg50doorgunner New Member

    Jan 24, 2010
    1:9 twist is considered a fast barrel for a .223. Fast barrels work well with heavier bullets, while slow barrels (1:12 twist) work well with lighter ones (50-55gr).

    The USMC Colt M-16A2 and A4 had 20" (1:12) barrels ideally suited for 55gr FMJ.

    Your (1:9) 14.5" barrel is ideally suited to heavier bullets. I agree with "Retired Grunt", try some 69gr.

    I load Hornady 68gr FMJ and Sierra Match King 69gr FMJ for my (1:9) 16" Colt M4 and achieve 1/2" MOA. BTW, your Bushmaster Carbon 15 is one of my personal favorites... a great rifle!
  10. Claude Clay

    Claude Clay New Member

    May 26, 2009
    Central CT
    go to 62gr. 69 is for 1/7. 55 for 1/10 and up.
    how many rounds through it so far? i don't buy into bbl break ins (for your getup) but seasoning a bbl is understandable. couple hundred rounds of copper bullets, cleaning after each 50 and no mag dumps. pace yourself by scoping each round.
    eotec is darn nice as has been noted, but for accuracy glass is necessary.
    Last edited: Apr 2, 2011
  11. RustyFN

    RustyFN Member

    Oct 2, 2008
    West Virginia
    A 1:9 is pretty standard for all of the AR's I have seen. A fast twist AR will be 1:7 twist. A 1:9 twist won't stablaize a bullet over 69 grains very well. I load the same Hornady 55 grain FMJ-BT for my Rock River 16" with 1:9 twist and get very good accuracy. I had four exploding target set at 100 yards. The spot you have to hit to set them off is the size of a quarter. It took me four shots to explode the four targets. That was with my front elbow resting on a table. I'll take that kind of accuracy any time.
  12. Thanks for all your help. I was already debating trying a different type of scope. Now I think I will, along with a heavier bullet.
  13. guntech59

    guntech59 New Member

    Dec 1, 2008
    Adirondack foothills
    Ahhhhh, no! M16A2 and newer variants all had 1/7" twists.
  14. Boris

    Boris Former Guest

    Oct 1, 2010
    Its not the weight that counts, its the length. The 62 grain projectile in M855 ball is as long as a 71 grain all lead core projectile. The less dense steel portion of the M855 projectile makes it longer for its weight.

    I have seen more than plenty of 1:9 twist barrels turn out spectacular groups with 75 grain projectiles.
  15. gun-nut

    gun-nut Member

    Jan 15, 2011
    I have the howa 1500 and the speer 55gr sp works well. I use 22.5 gr. of IMR 4198 and put them hole for hole on a calm day low humidity. On high humid days with wind i still clover leaf. Thats at 200 yards. If my mind serves me right i have a 1:10 twist and a 22" bbl.
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