Privacy guaranteed - Your email is not shared with anyone.

Welcome to Glock Talk

Why should YOU join our Glock forum?

  • Converse with other Glock Enthusiasts
  • Learn about the latest hunting products
  • Becoming a member is FREE and EASY

If you consider yourself a beginner or an avid shooter, the Glock Talk community is your place to discuss self defense, concealed carry, reloading, target shooting, and all things Glock.

AR-15 ammo question

Discussion in 'Black Rifle Forum' started by Petrie, Jan 26, 2010.

  1. Petrie


    Nov 26, 2008
    I have a DPMS AR chambered in 5.56 x 45 mm. Can I shoot any .223 I want out of it? I've only shot 55 gr so far. Can I run 70-80 out of it with no trouble? Are the heavier bullets longer? Will they jam into the rifling? Are the heavier bullets too long to fit in a magazine? I only have a 1/9 twist so I don't know that my gun could handle the heavier bullets anyway.
  2. Glock2008

    Glock2008 Gun User

    Jul 16, 2008
    Up north
    You can use any .223 rem ammo, but some of the heavier bullets are going to be inacurrate with a 1:9 twist and may not fit in your magazine. bullets in the 50-70 grain range are going to be your best bet for a 1:9 bbl.

  3. deadmonkey90

    deadmonkey90 Pro Bass Angler

    Feb 15, 2009
    NW Indiana
    Thanks, educational for me as well. I was planning on shooting 55gr 5.56 in my 18in bbl with a 1:8 twist
  4. lawman800

    lawman800 Juris Glocktor

    I read 55 grain for 1 in 7 and 62 grain for 1 in 9.
  5. mboylan


    May 11, 2007
    1:7 will stabalize the heavier 68 and 75 grain bullets. 1:9 will work for 55 and 62 grain bullets. I would not try 78 grain match bullets out of a 1:9 barrel. You would be wasting your money.
  6. pcar


    Sep 21, 2009
  7. KalashniKEV


    Sep 24, 2003
    Flip that and you'd have the optimal stabilizations:

    1/7- 62 grain- M855
    1/9- 55 grain- M193

    Mk. 262 Mod 1 is 77 grain, and wouldn't stabilize well from a 1/9.
  8. Onmilo


    Jul 10, 2005
    1-8 will shoot anything in the 52 to 77 grain catagory.

    The old favorite Match twist for shooting 80 grain bullets was 1-7.5

    I have found the 1-9 will stabalize the widest variety of bullet weights but does its best with 55-64 grain bullets.
  9. Kentak


    Jan 8, 2006
    Central Ohio
    It goes really, really fast out of the barrel, travels downrange, and, if you've done your part, hits what you're shooting at.
  10. marvin

    marvin sci-fi nut

    Mar 26, 2001
    greentown ind.
    not out of a ar but my savage bolt had a 1-9 twist and would shot 77 grain bullets very well. some will some won't
  11. den308

    den308 NOT A COOK

    Oct 31, 2004
    New England U.S.A.
    With FMJ ammo, nothing other than hitting your target. With lighter jacketed bullets they may spin apart from the centrifugal force imparted by the rifling. An observant friend would see a puff of gray "smoke" about 15 yards out from the barrel.
  12. Petrie


    Nov 26, 2008
    So, the two questions I really wanted answered were will the heavier bullets fit in an AR magazine? And will the bullets fit in the chamber? I've heard that some real heavy .223 rounds are so long that the chamber throat has to be reamed and that the rounds have to be loaded one at a time through the side because they are too long to fit in the magazine. Is that only the 90 grain bullets they use in NRA long distance shooting or does that apply to 80 grain bullets? I'm curious because I bought some federal tactical 55 gr 5.56 that just fit in my AR mags, and I heard the heavier bullets are longer. Are the longer bullets just sunk further into the case? Is the overal cartridge length of a 77 gr Siera match king the same as a 55 grain cartridge?