Page 2 of 2 FirstFirst 12
Results 11 to 16 of 16

Thread: Bullet Setback

  1. #11
    Hokey / Ancient JAD's Avatar
    Join Date
    Jul 2011
    Location
    Kansas City
    Ironically, if I had a .380, I'd carry FMJ in it.
    Ignore Alien Orders

  2. #12
    Site Supporter DocGKR's Avatar
    Join Date
    Feb 2011
    Location
    Palo Alto, CA
    As I've stated numerous times, Once a round has been chambered, DO NOT RE-CHAMBER IT for duty use. Do NOT re-chamber it again, except for training. This is CRITICAL!!!

    A large SWAT team in this area had a failure to fire from an M4 with Hornady TAP ammo during an entry--fortunately no officers were hurt and the suspect immediately threw down his weapon when the carbine went click instead of bang. After the incident was concluded, the team went to the range and expended the rest of their carbine ammo and had one additional failure to fire. This same team had 3 Hornady TAP rounds fail to fire in training a couple of years ago. When Pat Rogers was teaching a class at a nearby agency, there were 5 failures to fire using Hornady TAP ammo. In all 10 cases, there appeared to be good primer strikes, but no rounds fired. On analysis, the ammunition had powder and checked out otherwise.



    However, despite what appeared to be good primer strikes, two problems were discovered. First, when accurately measured, some of the primer strikes had insufficient firing pin indentations. The failed round from the potential OIS incident had a primer strike of only .013"—the minimum firing pin indent for ignition is .017". In addition, the primers on the other rounds were discovered to have been damaged from repeated chambering. When the same cartridge is repeatedly chambered in the AR15, the floating firing pin lightly taps the primer; with repeated taps, the primer compound gets crushed, resulting in inadequate ignition characteristics--despite what appears to be a normal firing pin impression.

    Rechambering pistol ammunition can also cause issues, including both failures to fire from primer damage and increases in pressure as a result of bullet set-back: http://le.atk.com/downloads/technica...s-Pressure.pdf

    The comment below is written by a highly skilled combat veteran I know regarding his experience fighting OCONUS with ammo that had been re-chambered:

    "I have relayed this story to a few of you before but here it is again. Pay attention to what DocGKR has stated because it could very well save your life. My first shooting in Iraq I threw my M4A1 on semi and ATTEMPTED to fire a controlled pair (First round functioned striking the threat and the second round did not function). I then transitioned to my secondary (Glock 19 shooting ball) and had a failure to fire on my first round....I was Waaaaaay behind the power curve at this point. At this point I was contemplating all of my various bad life decisions which had lead me to that point in my life and grabbed an M240B and solved the problem. I AM VERY LUCKY TO STILL BE UPRIGHT AND BREATHING TODAY....the cause of these malfunctions you ask? Repeated chamberings of the same ammo. I made a decision that day that my life was more important than following archaic rules written by those who sit behind desks and started shitcanning rounds after i was forced to clear weapons on U.S. Military installations. The .gov can fuckin bill me."
    In addition, as noted above, DOE security personnel have noted this same issue, not only with carbines, but also with .40 Glocks.

    A person might get away with re-chambering several times, but it could also kill the primer or intrude the projectile into the cartridge case in as little as 3 re-chamberings. Is a life worth the cost of a single cartridge?

    Keep the pistol in your holster, remove the holster from your belt and place it in the lock box. When you need the pistol again, re-attach the holster to your belt.

  3. #13
    We are diminished
    Join Date
    Feb 2011
    Quote Originally Posted by DocGKR View Post
    Keep the pistol in your holster, remove the holster from your belt and place it in the lock box. When you need the pistol again, re-attach the holster to your belt.
    That's what I do.

    As for the Luckygunner Lab thing, there are a lot of factors that need to be determined. Powder charge, bullet design, etc. can all affect the pressure of an overseated bullet. In the instant case, e.g., if it was the low-pressure 165gr "Reduced Recoil" Gold Dot which is popular with many LE agencies then the overseating would be much less likely to cause as dangerous a spike as, say, a round loaded to max pressure.

    Suggesting that it's not dangerous based on one backyard test is, imho, irresponsible. There are far too many people with personal experience of overpressure/overseated rounds causing substantially damage to shrug it off as a myth. If you read the comments, for example, there is one person who said he's seen serious overseating with his 357 SIG Gold Dots and apparently, thanks to Luckygunner, won't be worried about shooting them. I've worked with two large federal LE agencies that have suffered multiple damaged guns from shooting 357 SIG Gold Dot with just a few chamberings per round. One of those agencies also all but destroyed an entire shipment of guns early in the days of 357 SIG with another brand of ammunition that had particularly serious problems with maintaining neck tension.

    When I go to the range, the first round I fire is the round that was in the chamber when I drove there whenever possible. If for some reasons I'm forced to clear my pistol prior to shooting, the JHP gets put somewhere specifically designated for once-chambered JHPs and gets fired as a practice round at my next opportunity. That way:
    • it never gets chambered more than twice, and
    • I never rely on it for self-defense once it's been chambered more than once.

  4. #14
    Name:  EF929FA5-95CA-464C-AEA8-A0547A87C211.jpg
Views: 124
Size:  81.9 KB

    I was casually loading mags before heading to the range today and pulled this round from a new box of 124gr Lawman. A good reminder to actually look at what you’re putting in your mags.

  5. #15
    Site Supporter OlongJohnson's Avatar
    Join Date
    Mar 2015
    Location
    "carbine-infested rural (and suburban) areas"
    I always check the height of all the rounds in the rack when I pull it out of the box. I've seen one where an edge row was progressively set back further as you went toward the end of the row. Almost certainly dropped on that corner.
    .
    -----------------------------------------
    Not another dime.

  6. #16
    I think you’re right as it was the last round in the box. But it sure may me unload the rest of my mags to check

    Quote Originally Posted by OlongJohnson View Post
    I always check the height of all the rounds in the rack when I pull it out of the box. I've seen one where an edge row was progressively set back further as you went toward the end of the row. Almost certainly dropped on that corner.

User Tag List

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •