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5.56 Ammo, How To ID Bullet Weight?

nunnnunn Forums Admins, Member, Moderator Posts: 36,085 ******
edited February 2007 in Ask the Experts
Without busting it down and weighing a bullet, that is.

My issued M16A1 was made in 1975, and has the older 1:9 (I think) twist barrel. It shoots well with the issued 55 grain .223 Remington ammo.

I have on hand a quantity of GI 5.56 ammo and I don't know what the bullet weight is. I am hoping one of you can tell me from the available markings whether this is 55 grain or 62 grain ammo.

Headstamp is L C 8 1. I presume that means Lake City Arsenal, made in 1981.

The ammo is not in boxes, but on bandoliers, and the bandolier is marked, "BALL M193" and "LC-81K001-186."

I called my rifle guy and he said, "Just shoot it, and if it shoots OK, it is right for the rifle."

I would sorta like to know. If it is 55 grain, I will shoot it. If it is heavier, I may try to swap it for some of the same with the lighter bullets.

Thanks.

Comments

  • nononsensenononsense Member Posts: 10,928 ✭✭✭✭
    edited November -1
    Nunn,

    Two separate sources stipulate either a 55 gr. or 56 gr. lead jacketed cannelured bullet.


    M193 Cartridge, 5.56mm, BALL. Unpainted tip. For use against personnel and unarmored targets.

    Variously referred to as: 5.56 Ball, .223 Armalite, .223 Remington Special, 5.56 x 45mm.

    Suitable for use in most weapons with a 1:12" barrel twist. 5.56mm Rifles: M16, M16A1, M16A2, AR15, H&K, Galil, Ruger, FN, SIG, other compatible systems.


    Best.
  • nunnnunn Forums Admins, Member, Moderator Posts: 36,085 ******
    edited November -1
    Thanks. I believe it will work fine.
  • tsavo303tsavo303 Member Posts: 8,913 ✭✭✭
    edited November -1
    Based on the age, It might be 1-12
  • tsavo303tsavo303 Member Posts: 8,913 ✭✭✭
    edited November -1
    quote:Originally posted by tsavo303
    Based on the age, It might be 1-12

    count the twists on the cleaning rods when it spins with the bore. 1-9 you would get a little over 2 revolutions in your 20", i bet you get 1.75 revolutions on the 1-12
  • ammo guyammo guy Member Posts: 810 ✭✭✭
    edited November -1
    The bullet weight of the M193 is 55 gr, the green tip(M855) is the 62 gr weight.
  • BHAVINBHAVIN Member Posts: 3,490 ✭✭
    edited November -1
    I would think that your barrel twist rate would be stamped on the barrel in front of the front sight. This may not be the case as I have not dealt with M16's from that era. 1/9 is the most common today. M193 is 55g ammo.
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