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Thread: how short 75gr from a 1-9" can you go?

  1. #11
    Gunco Good ole boy tanvil's Avatar
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    I have a 16'' 1-9 Fulton that shoots them (75gr.) just fine. It does not keyhole the 62 gr. Federal greentip s/c ammo, but it won't shoot them very well. I get a softball sized spread w/ 5 rds. at 100 with it. The 75's are between 1-1.5 inches most of the time shooting prone from a sandbag.

  2. #12
    GuncoHolic kernelkrink's Avatar
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    4th, the original AR15s/M16s issued in 'Nam had 1 in 14" twist bbls. This was barely enough to stabilize the 55 grain ball ammo then issued. It would fly straight through the air but when it hit flesh, they instantly lost stability and started tumbling end over end, often bending into a bannana shape and breaking up. Think minature boomerang buzzsaw flying through you at 3,000FPS with little chunks flying off. This caused the terrible wounds that the higher ups thought would allow a small .22 to equal the performance of the .30 it replaced. All was well until arctic temp testing in Alaska revealed that the colder, denser air caused the bullets to destabilize in flight and tumble in midair. As a result, one of the many "improvements" to the M16 was a change to a faster 1 in 12" twist. No more tumbling bullets in the arctic, but now the bullet was so stable it drilled a 1/4 hole straight through people and got it's rep as a poor stopper.

    The newer SS109 bullets are designed to break apart in the middle when they hit, which makes 2 wound tracks and of course the pieces tend to tumble. In theory anyway, a better stopper over the 55gr ball. So the US Army adopts that round as the M855, then turns right around and adopts the M4 Carbine version to fire it with a 1 in 7" bbl twist. Unfortunately, that breakup effect is dependant on velocity, so the shorter M4 with it's lower muzzle velocity results in less than spectacular wounding with the new cartridge. The Jarheads kept their 20" bbls though, and report generally good results. There is supposed to be a new M4 specific round out, the M855A1 that is a copper and steel lead free design. Haven't seen any field reports on it yet, might be the solution, might not.

    In any event, if ya ain't in the military any more the Hague prohibitions on HPs no longer apply. There are some great hollowpoints out there that will get the job done.

  3. #13
    Gunco Addicted for life j427x's Avatar
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    i would be willing to bet that 4ths 7"-- 1-9" twist rate super shortie would stabilize the 75gr ammo OK out to 50-100M. about as far as you would want to shoot with a 7" anyway.


    my wolf 63gr is acting like it wants to tumble probably due to low velocity , improperly sized bullets or a bit of each. so it is a ammo thing--not the barrel.

    the wolf 75gr is better ammo with better powder and bullets so it ain't near the edge of stability.

    i did fire a few of the tula 55rg that a buddie dropped off. it showed low velocity but had enough push to cycle the 11.5" OK so it ain't as bad as that batch i got.

    it is wanting to go "old-west" like the 63gr wolf . if it hits a leaf, a twig a piece of paper or thin cardboard it goes " werrrrr!" so it is just like the old west movies.

    but i think it is the AMMO-- possible the bullets and powder quality problem.

    good 55gr and 63 are FINE and the wolf 75gr are fine in the 11.5" 1-9"

    when i was shooting .45 acp tula the other day i has a couple 45s tumble off --old west style too--LOL!

  4. #14
    Gunco Member ironhead7544's Avatar
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    Quote Originally Posted by kernelkrink View Post
    4th, the original AR15s/M16s issued in 'Nam had 1 in 14" twist bbls. This was barely enough to stabilize the 55 grain ball ammo then issued. It would fly straight through the air but when it hit flesh, they instantly lost stability and started tumbling end over end, often bending into a bannana shape and breaking up. Think minature boomerang buzzsaw flying through you at 3,000FPS with little chunks flying off. This caused the terrible wounds that the higher ups thought would allow a small .22 to equal the performance of the .30 it replaced. All was well until arctic temp testing in Alaska revealed that the colder, denser air caused the bullets to destabilize in flight and tumble in midair. As a result, one of the many "improvements" to the M16 was a change to a faster 1 in 12" twist. No more tumbling bullets in the arctic, but now the bullet was so stable it drilled a 1/4 hole straight through people and got it's rep as a poor stopper.

    The newer SS109 bullets are designed to break apart in the middle when they hit, which makes 2 wound tracks and of course the pieces tend to tumble. In theory anyway, a better stopper over the 55gr ball. So the US Army adopts that round as the M855, then turns right around and adopts the M4 Carbine version to fire it with a 1 in 7" bbl twist. Unfortunately, that breakup effect is dependant on velocity, so the shorter M4 with it's lower muzzle velocity results in less than spectacular wounding with the new cartridge. The Jarheads kept their 20" bbls though, and report generally good results. There is supposed to be a new M4 specific round out, the M855A1 that is a copper and steel lead free design. Haven't seen any field reports on it yet, might be the solution, might not.

    In any event, if ya ain't in the military any more the Hague prohibitions on HPs no longer apply. There are some great hollowpoints out there that will get the job done.
    I was a 45B20 Small Arms Repair 69-72 in the Army. The 1 in 14 barrels had no lining and burned out the throats very quickly on full auto. When they came into the shop we replaced them with the newer 1 in 12 barrel that had a stellite liner or later around 1971 a chrome plated bore. All of the "black barrels" as we called them would throw nothing but keyholes even at 25 yards. That's probably where the M16 got the tumbling bullets legend.

    Concerning the 75 gr bullet in the 1 in 9, bullet quality can be good enough that a bullet will be accurate in a twist not considered correct for it. I had a 1 in 7 that shot the light match bullets very accurately.

  5. #15
    White Cracker 4thIDvet's Avatar
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    Thumbs up Super interesting info guys.

    ironhead. Sorry we gave you all that work. But if we heard a twig snap 100 guys went full auto until the barrels glowed.
    Is cherry red bad for a barrel?
    I dont know if we hit a damn thing. But they stopped shooting back. So I guess my bullets were tumbling, hell I dont know.
    "Man needs but two things to survive alone in the woods. A blow up female doll and his trusty old AK-47" - Thomas Jefferson 1781


  6. #16
    Treehuggin Gun Nut! bulletdodger's Avatar
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    Kernelkrink is correct on his account of the 1 in 14 twist. Ironhead, I do not doubt you saw many burned out barrels that caused bullet tumble, but a brand new rifle with a 1 in 14 twist will duplicate the terrible wounding potential the Viet Cong feared. The bullet does not tumble in flight, but it is so barely stabilized the slightest impact with anything, (including a body), would cause the bullet to go careening off course often exiting a body sideways causeing wounds seemingly disproportionate to the bullet's size. While the bullet was not reported to tumble in cold weather it did cause it to fail the accuracy test criteria set forth by the military. It was rather stupid of our military not to take advantage of this twist rate at least in Viet-Nam not just for it's wounding potential, but also the fear it generated in the Viet Cong. The 5.45x39mm has a similar wounding potential with it's built in tumble and still retains it's accuracy potential. We could have issued a different twist rate in cold weather battlegrounds should it have become necessary. I would intentionally seek a barrel with that 1 in 14 " rate should I ever purchase another upper for my Colt. Small hole in, small hole out sucks, especially for a lung shot. In the event of a lung hit it's very likely the person will not immeadiately realize he has been shot and shoot back at me.

  7. #17
    Gunco Addicted for life j427x's Avatar
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    another odd thing about wolf 75gr i have stumbled on, is that i think it shoots better through 1-9"( that is actually 1-8.75") and one in 8" than it does in 1-7".


    accuracy in the 1-9" savage bolt guns is pretty good just over 2" avg. once in a while a group will dip down to 1.5"

    with the one in 7" ar-15 it is opening up to 2.75" and sometimes pushing 4" !

    the 1-9" ar 15s are pulling in the 2"+ range. the avg around 2.5"

    my best guess is the russian bullets are sort of spotty. but not near as bad as the tula 55gr that was all over the place.

    so far all the 1-9" barrels in ar-15,AK, bolt gun and SBR seem to be stable with the 75gr wolf.

    accuracy is another matter. some of the barrels do pretty darn good while others are the edge of government acceptability with the load.


    before i stocked up on wolf or tula i would certainly shoot a decent batch of it first to see how it runs in your set up. as it seems to run better in some than others.

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