DK Firearms

Re. 22-250Rem . . What I Learned . . .

The #1 community for Gun Owners of the Gulf Coast States

Member Benefits:

  • Fewer Ads!
  • Discuss all aspects of firearm ownership
  • Discuss anti-gun legislation
  • Buy, sell, and trade in the classified section
  • Chat with Local gun shops, ranges, trainers & other businesses
  • Discover free outdoor shooting areas
  • View up to date on firearm-related events
  • Share photos & video with other members
  • ...and so much more!
  • FrommerStop

    Master
    Rating - 0%
    0   0   0
    Joined
    Apr 7, 2016
    Messages
    6,897
    Points
    113
    Location
    NWFL
    WR, in your above link it does not say under what "normal" hunting,target,or even plinking at a dirt pit,conditions the "poof" happens. What gun,what action,bbl condition (rough with tool marks),fwd velocity,rotational velocity,bullet makeup/design,etc. that a shooter could expect to poof a bullet after having departed the bbl,and not having hit ANYTHING on the way to the target.
    I would suspect that the bullet comes apart AFTER it has left the bbl. This would,at least to a great degree,be due to centrifugal force. I have seen bullets spun at close to a half million revs and hold together. No . . not a .224" 35gr that is designed for a 22Hornet.
    I personally have shot a M60 for a duration that is long enough,that the bbl is cherry red and semi transparent. This,when the bbl is subjected to 80-100 mph wind. Also salt spray and a 25knot wind. I have seen a long bbl M2 50BMG treated the same and fire fine.
    I stand by my post #54 & 55. I feel that to "poof" a bullet the shooter would have to intentionally put together/combine the things that would cause this to happen.
    Has it happened in the past ?? . . YES . . but it was most likely due to the shooter had suffered a "POOF" of the brain somewhere in his past.
    The above are just one mans opinion. --- SAWMAN
    Great observations about personal experience which is the most valuable. For ARs I have seen videos of the barrels blowing up when fired to very high temperatures with a full auto receiver. But the AR is not really designed for sustained FA fire
     

    SAWMAN

    Master
    Rating - 100%
    9   0   0
    Joined
    Oct 21, 2012
    Messages
    13,937
    Points
    113
    Location
    Cantonment,Fla.
    I am a huge fan of P.O. Ackley. His work with inside,outside,and terminal ballistics is what laid the groundwork for modern reloading.
    He did alot of work for the US Military as far as armor pierceing capabilities of small fast projectiles. He loved the 220Swift and he finally achieved 5000fps using a 20gr brass bullet.
    I actually got to meet him once at a small,obscure military facility in Calif. Later on he sent several of us signed copies of his most famous work.
    There is tons of info in these two volumes. Great read. --- SAWMAN
     

    Attachments

    • 20190408_142653.jpg
      20190408_142653.jpg
      359.2 KB · Views: 200
    • 20190408_142345.jpg
      20190408_142345.jpg
      290.1 KB · Views: 200
    Last edited:

    wildrider666

    Master
    Rating - 0%
    0   0   0
    Joined
    Sep 26, 2012
    Messages
    8,753
    Points
    113
    Location
    Panama City Beach, Fl
    I think "normal" depends on the users perspectives. The examples below are folks doing normal gun stuff. A common link to the Poof phenomena is it occurring with homemade reloaded ammo. I don't recall seeing any references to a Factory cartridge Poof, but there are numerous cases of recall for "overpressure" so it's not outside the realm of possiblity.

    This Link refers to twist rate, velocity driving RPM + heat: creating Poof. A "TOO FAST" Twist Rate can be offset by reducing MV.
    http://bulletin.accurateshooter.com/2008/06/calculating-bullet-rpm-spin-rates-and-stability/

    These are Links to Poofs with some specific data and conditions from OP but Commenters also add their experiences with it. I didn't check their data in order to see if loads were within specs or exceeded them.

    Poof from AR:
    https://www.thehighroad.org/index.php?threads/are-my-bullets-disintegrating-in-flight.821778/
    Poof from 6mmAI
    https://forum.snipershide.com/threads/bullet-failure-midair-disintegration.51621/
    Poof boiling hot rifle
    https://www.northeastshooters.com/xen/threads/bullets-disintegrating-mid-flight.312384/

    This vid shows a M16 cookoff a couple rounds from a hot gun.
    https://m.youtube.com/watch?v=fO18uWPcnko

    Link to the Cookoff Test for 7.62
    https://www.sciencedirect.com/scien...0385https://m.youtube.com/watch?v=fO18uWPcnko

    All I'm saying is projectiles can disintegrate in flight, it not as rare as a unicorn, it's documented and formally addressed. Same thing cartridge cookoff. You mileage may vary and that's fine.
     
    Last edited:

    MarkS

    Master
    Rating - 100%
    2   0   0
    Joined
    Sep 26, 2013
    Messages
    3,280
    Points
    113
    Location
    Baker,Fl.
    My brother had our father send him welding gloves so he didn’t burn his hands changing barrels when he was in Vietnam (June 67-68 A Shau Valley- June 68-69 P School cadre)
    He told me that some of the fire-fights he was in his rifle would get so hot that the rounds would “cook off”
    forcing a barrel change. The SeaBees that he liberated barrels from probably still hold a grudge seeing that he drank their beer and swiped their barrels


    Sent from my iPhone using Tapatalk
     

    SAWMAN

    Master
    Rating - 100%
    9   0   0
    Joined
    Oct 21, 2012
    Messages
    13,937
    Points
    113
    Location
    Cantonment,Fla.
    The bullets in the first two links are spinning at 312,685 and 286,200. Even a 1:7 AR shooting a 55gr or even a 62gr is spinning just as fast.
    While having a poof is a great "out" for missing your target,most shooters will never expierance this in their lifetime. I have not. But it happens to jj all the time.
    While I am not saying this never happens,I am left wondering the potential reasons for this occurring. In the above case it seems to have happened to the guy shot after shot. So the same thing happened time after time. In the above cases the shooters seemed to be expieranced. So I am wondering why would they allow their bbls to heat up ?? Especially if they expected any degree of accuracy.
    Putting the above two shooters expierances together,you can rule out quite a few things. About the only thing that I am left with is - - -> something wrong with the bullets ?? A bad batch/lot/run ?? Maybe the lead inside the copper was not formed properly. Off center ?? Air gaps ?? Some parts hard/dense and some parts soft/porous ??
    You are right about it never happening to/with factory loads. Wonder why ?? Something is different in just that.
    I just might buy a box of lightweight "varmint" bullets. They make some that are advertised for a 22Hornet. IIRC they are 35gr and have a wide nose with alot of exposed lead. I have a 1:7 twist,24" AR that I could try them in. Move the target up to 50yds and see what happens. Could be I discovered a great dove/quail load. --- SAWMAN
     

    FLT

    Master
    Rating - 0%
    0   0   0
    Joined
    May 15, 2017
    Messages
    3,849
    Points
    113
    Location
    Havana
    I believe it’s possible, but I’ve never witnessed it. It would take a liberal dose of of speed to generate enough centrifugal force to disnergrate a bullet .
     

    SAWMAN

    Master
    Rating - 100%
    9   0   0
    Joined
    Oct 21, 2012
    Messages
    13,937
    Points
    113
    Location
    Cantonment,Fla.
    Yep, . . . rotational velocity. Forward speed has very little to do with the "poof".
    I suppose that if you hit a tuft of grass,the fwd vel will have something to do with it more at 4000fps vs 3000fps. --- SAWMAN
     

    FrommerStop

    Master
    Rating - 0%
    0   0   0
    Joined
    Apr 7, 2016
    Messages
    6,897
    Points
    113
    Location
    NWFL
    It would seem that larger diameter bullets would be more susceptible to coming apart relative to centrifugal force than smaller diameter bullets. But not too many full bore loads make 4000 fps second. Maybe there are some antiaircraft cannon loads that get going really fast. But such loads are not really highly frangible and require an explosive charge to fragment.
     

    SAWMAN

    Master
    Rating - 100%
    9   0   0
    Joined
    Oct 21, 2012
    Messages
    13,937
    Points
    113
    Location
    Cantonment,Fla.
    I shot several 125gr NosBalTips (.308") out of my 30-378Wby Mag at 4100 or so. Not accurate but hit target. It had a 1:10 twist bbl. (295,200RPM)
    This was the older varmint jacket version also. Now the "hunting" version is made similar to a Accubond. --- SAWMAN
     
    Last edited:

    wildrider666

    Master
    Rating - 0%
    0   0   0
    Joined
    Sep 26, 2012
    Messages
    8,753
    Points
    113
    Location
    Panama City Beach, Fl
    The formula: MV X 720/Twist Rate (TR in inches) = Projectile RPM. We use RPM, in physics it's Spin angular velocity. There is a direct relationship between MV and TR creating RPM. Increase/decrease MV will increase/decrease RPM from the same TR. Likewise, if MV is a constant: Faster TR will produce higher RPM than a Slower TR.

    If we want to look at the Centrifugal Force generated, the Sum is still dependent on RPM (MV X 720/TR). RPM greater/less also have a direct relationship to greater/less Centrifugal Force.

    Projectile @ Mass 52gr, Radius 0.112, Angular Velicoty 300000 RPM, has a Centrifugal Force of 2127 lbf.
    If we slow the RPM to 200000, Force is reduced to 945.3lbf
    RPM @ 150000, Force drops to 531.7lbf

    Add the heat sources, projectile material design and composition (short, thin jacket material or imbalance defect) and its understandable some fail.

    Of all places, Wiki even references the issue under "Bullet" Any asymmetry in the bullet is largely canceled as it spins. However, a spin rate greater than the optimum value adds more trouble than good, by magnifying the smaller asymmetries or sometimes resulting in the bullet exploding midway in flight.
     
    Last edited:

    FrommerStop

    Master
    Rating - 0%
    0   0   0
    Joined
    Apr 7, 2016
    Messages
    6,897
    Points
    113
    Location
    NWFL
    The formula: MV X 720/Twist Rate (TR in inches) = Projectile RPM. We use RPM, in physics it's Spin angular velocity. There is a direct relationship between MV and TR creating RPM. Increase/decrease MV will increase/decrease RPM from the same TR. Likewise, if MV is a constant: Faster TR will produce higher RPM than a Slower TR.

    If we want to look at the Centrifical Force generated, the Sum is still dependent on RPM (MV X 720/TR). RPM greater/less also have a direct relationship to greater/less Centrifical Force.

    Projectile @ Mass 52gr, Radius 0.112, Angular Velicoty 300000 RPM, has a Centrifical Force of 2127 lbf.
    If we slow the RPM to 200000, Force is reduced to 945.3lbf
    RPM @ 150000, Force drops to 531.7lbf

    Add the heat sources, projectile material design and composition (short, thin jacket material or imbalance defect) and its understandable some fail.

    Of all places, Wiki even references the issue under "Bullet" Any asymmetry in the bullet is largely canceled as it spins. However, a spin rate greater than the optimum value adds more trouble than good, by magnifying the smaller asymmetries or sometimes resulting in the bullet exploding midway in flight.

    Diameter also has a dramatic effect.
    Fc = mv2/r, where Fc = centrifugal force, m = mass, v = speed, and r = radius. An object traveling in a circle behaves as if it is experiencing an outward force. This force is known as the centrifugal force. ... The equation above shows that the force depends on v-squared over r.
     

    wildrider666

    Master
    Rating - 0%
    0   0   0
    Joined
    Sep 26, 2012
    Messages
    8,753
    Points
    113
    Location
    Panama City Beach, Fl
    Diameter also has a dramatic effect.
    "An object traveling in a circle....."


    That would be "Orbital Angular Velicoty" like the Earth circling the Sun. Orbital Angular Velocity refers to how fast a rigid body's centre of rotation revolves about a fixed origin.

    Spin Angular Velocity refers to how fast a rigid body rotates with respect to its centre of rotation. Like the Earth spinning on its axis.

    I blewthe spelling of centrifugal. I cheat and use this. Radius being 1/2 the diameter.
    https://www.omnicalculator.com/physics/centrifugal-force
     

    wildrider666

    Master
    Rating - 0%
    0   0   0
    Joined
    Sep 26, 2012
    Messages
    8,753
    Points
    113
    Location
    Panama City Beach, Fl
    Poof Vid?
    Guy Posted this narrative with video: "Speer 52gr hollow point being fired out of a 223AI with a 7 twist barrel. Was fire forming brass and sighting in the scope on a brand new build. Couldn't find the impacts so I chambered a round and watched what was going on outside of the scope when I noticed a white puff of smoke approximately 25 yards out. Bullet jacket is separating from the lead core due to rotational forces. Rifle was built and chambered to use the Berger 90gr VLD."

    https://m.youtube.com/watch?v=aFLed1clSk4

    A small grayish plume is visible down range immediately after the shot but no discernable noise with it. There is a second "noise" 1.5 to 2 seconds after the shot that is unidentified. Full or partial projectile breakup? Prior aimed shots didn't hit target. This shot was not aimed. Even against the odds, did part of the projectile hit something down range? Maybe the noise was from a source unrelated to the SHOT. more questions than answers.

    Another one but no data.

    https://m.youtube.com/watch?v=4IDwqpL_H_E
     
    Last edited:

    SAWMAN

    Master
    Rating - 100%
    9   0   0
    Joined
    Oct 21, 2012
    Messages
    13,937
    Points
    113
    Location
    Cantonment,Fla.
    What happens when a bullet flying on "the edge" hits one of them big bees ??
    ANYWAY . . . wonder if any of the Valkyrie shooters,with the 1:7 twist bbls are having any problems ??
    Or any of the 22-243 Middlested shooters ?? --- SAWMAN
     
    Top Bottom