In order to participate in the GunBroker Member forums, you must be logged in with your GunBroker.com account. Click the sign-in button at the top right of the forums page to get connected.
Options

Data for 55 grain FMJBT w/ 1 in 9 twist AR15

1988z011988z01 Member Posts: 602 ✭✭✭✭
edited June 2011 in Perry Shooter Competition Shooting and Reloading Forum
Hey There:

I'm looking for some load data for an AR15 with a 1 in 9 inch twist. I've got 55 grain FMJBT w/Can. bullets. I have all the typical load data, but I don't have anything specific for a rifle with a 16 inch barrel with a 1 in 9 inch twist.

Thanks
· Share on FacebookShare on Twitter

Comments

  • Options
    Hawk CarseHawk Carse Member Posts: 4,368 ✭✭✭
    edited November -1
    The barrel length and twist do not affect the powder charge for a given weight of bullet.
    · Share on FacebookShare on Twitter
  • Options
    dcs shootersdcs shooters Member Posts: 10,969
    edited November -1
    Just use the load data you have.
    The 55gr will just be a plinking load for the 1/9 twist.
    · Share on FacebookShare on Twitter
  • Options
    MobuckMobuck Member Posts: 13,785 ✭✭✭✭
    edited November -1
    This not a recommendation!
    My loads using LC cases, CCI#41,Privi 55 FMJBT,and 25.5 grains of surplus 844 gives close to 3200 fps from a 24" and 2900 fps from a 16"(both 1-9 twist) measured 10' from the muzzle.
    Every rifle will be slightly different but these loads were fired through 2 of each barrel length over the Chrony. Accuracy was under 1 1/2" with 9x=adequate for the intended purpose.
    I'm confident enough in this loading to load up about 5K for future needs.
    · Share on FacebookShare on Twitter
  • Options
    MobuckMobuck Member Posts: 13,785 ✭✭✭✭
    edited November -1
    Just corrected my barrel length. The 3200 fps was from a 24" 1-12 twist bolt action rifle not a 20" AR. A 20" would expected to be 1/2 way between.
    · Share on FacebookShare on Twitter
  • Options
    BUCKAWHOBUCKAWHO Member Posts: 966 ✭✭✭✭
    edited November -1
    Hi...I use both 25 gr. 748 or 22 gr. 4198 behind 55 gr. Hornady FMJBTs in my 16 in. 1/9 twist Colt. BT
    · Share on FacebookShare on Twitter
  • Options
    sandwarriorsandwarrior Member Posts: 5,453 ✭✭✭
    edited November -1
    5.56 or .223 chamber?

    You can start using .223 data for a 5.56 chamber. But, you won't be limited when you get to the top. The 5.56 runs hotter than .223. DON'T keep going up with the .223 chamber

    Anyhow, as you probably know, the 1-9" twist is optimized for heavier bullets. Pushing 55 gr. bullets to normal speeds of 3100-3200 is fine. The problem is bullet concentricity exacerbates accuracy problems when bullets are twisted too fast. So, you may not get the best accuracy from 55 FMJ bullets. But, 55 FMJ's aren't known for the best accuracy in .224" bullets anyways.

    I would just start @ 25 gr. of H4895, or IMR8208 data and work up. For dumping loads TAC, X-Terminator, Win 748, BL-C2, AA2230, H322 will all work fine starting at the given starting points and working up.
    Accuracy loads for me and lighter .224" bullets are with H4198 and AA2015. Both of those can be found on www.hodgdon.com reloading data.

    -good luck
    · Share on FacebookShare on Twitter
  • Options
    MobuckMobuck Member Posts: 13,785 ✭✭✭✭
    edited November -1
    The 24" bolt rifle is a Wby Vanguard(Howa) stamped .223.
    The 16" is a DelTon 5.56 not chrome lined.
    · Share on FacebookShare on Twitter
Sign In or Register to comment.