Setback on .40

Discussion in 'Cop Talk' started by Aux Bear, Oct 1, 2012.


  1. Overall Case Length is only a Maximum Length
    Heavier bullets (with same nose profile) are longer and will be loaded deeper into the case, hence less margin of error. I always suggest students save a tray from a box of ammo that allows cartridges to sit loosely in the tray. Put em in nose down and visually check to see if any cartridge looks "short".

    Parent case 10mm Auto
    Case type Rimless, Straight
    Bullet diameter .400 in (10.2 mm)
    Neck diameter .423 in (10.7 mm)
    Shoulder diameter .423 in (10.7 mm)
    Base diameter .424 in (10.8 mm)
    Rim diameter .424 in (10.8 mm)
    Rim thickness .055 in (1.4 mm)
    Case length .850 in (21.6 mm)
    Overall length 1.135 in (28.8 mm)
    Case capacity 19.3 gr H2O (1.255 cm³)
    Rifling twist 1 in 16 in. (406 mm)
    Primer type Small Pistol
    Maximum pressure 35,000 psi (240 MPa)
     

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  2. I picked up 150 rds. of new .180 Rangers. Now I will grab my caliper and for Chuckles and Grins I'll measure and record all my current duty carry rounds to see where they are today, and sample the new ones as a comparison. Back later with the info for anyone who is interested. Thanks for all the input everyone! It is appreciated.
     

  3. old_pigpen

    old_pigpen Huh? What?

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    I got a spec sheet from Winchester's website for the .40 JHPs I use. Per the sheet, the OAL is 1.110. I checked several of the .40 rounds that have been chambered repeatedly, and they came in at that spec. However, I did find one round that came in at 1.100. It looks more beat up than the others, so I suspect that one was chambered more than the others. That one round has been set off to the side - it's not worth risking my weapon or my hand.

    Aux Bear, thanks for staring this thread!
     
  4. JBS

    JBS

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    All my duty ammo is fired for qualification at the end of the qualification year. The only time I will drop the slide on a round is at the range and as expected it goes down range. When I load, unload, or top off away from the range I ride the slide to prevent bullet setback. I know exactly what "in full battery" looks and feels like in all my weapons. I think sling shotting and full slide drop loading away from the range has been taken to the extreme and the result is un-needed bullet setback, case dents, and loose bullets. In the old days a ride the slide was called a “silent load” and it was not looked down on.
     
  5. ricky

    Millennium Member

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    I am shocked at 3 years with the same ammo!!

    We get fresh ammo every 3 months.
     
  6. Most of my co-workers are not into firearms at all and hearing other on CT I would think it's safe to say the majority of LEOs are not. They show up to the annual qual, do the required training days, and that is it. I would argue that training the masses to ride the slide teaches bad habits they will go to under stress. I remember hearing stories of guys with revolvers trying to pocket their brass under stress because that's what they did during practice.

    Take the admininstrative load for example. I was taught almost 14 years ago to load up, holster, pop out the mag while in the holster, add a round to the mag, and seat the mag while in the holster.

    In the last year we've realized a training oppotunity and developing muscle memory is being lost.

    Now we are encouraged to get into a proper stance, draw from the holster, perform an emergency reload, then a tac reload, scan and then holster. First mag then gets topped up.

    We get our duty ammo replaced every two years and if anyone has issues with their ammo we can get it replaced earlier.

    Our old duty ammo gets used on outdoor training days since we usually qual on our indoor range with green ammo. We have never had an issue with old duty ammo.

    Train the way you fight.
     
    #26 bccop, Oct 3, 2012
    Last edited: Oct 3, 2012

  7. Its actually 100% true. Which is why they changed everything. Heard a story of a PO who was killed. When they got to him, he had a handful of empty brass. A

    After that they changed it to not picking any magazines or brass up until done with training.
     
  8. Kingarthurhk

    Kingarthurhk Isaiah 53:4-9

    7,587
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    So, I guess the moral of the story is I should pick a different round when I rack the slide before I go out every day?
     
  9. Wxcuse my abscence - I've been out on details the past 3 days. I did measure my carry rounds and a box of brand new - never loaded Winchester .40 T- Series, RA40T.

    Left column is the meas. of the virgin rounds, center column is the meas. in inches., right column is a meas. of my carried, repeatedly chambered rounds:

    0 1.102 0
    0 1.103 0
    0 1.104 2
    0 1.105 2
    0 1.106 0
    0 1.107 0
    2 1.108 0
    4 1.109 3
    3 1.110 6
    1 1.111 5
    4 1.112 8
    2 1.113 10
    4 1.114 7
    4 1.115 12
    3 1.116 7
    4 1.117 13
    4 1.118 11
    3 1.119 8
    3 1.120 9
    1 1.121 7
    0 1.122 4
    1 1.123 4
    1 1.124 3
    0 1.125 4
    3 1.126 5
    3 1.127 4
    4 1.128 4
    2 1.129 3
    0 1.130 0

    Each round was carefully measured and the the round rotated to assure it was fuly seated. The highest read obtain is what was reported.

    So, what do you pros think? What would be an acceptable cut off point? The 1.085 projected min.? Or some other dimension? Are they, all good? Thoughts?
     
    #30 Aux Bear, Oct 7, 2012
    Last edited: Oct 7, 2012
  10. Sorry guys. This forum doesn't like columns! Fixed it twice and it's still screwy to read.
     
  11. razdog76

    razdog76 Heavy Mettle

    3,620
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    I think it would be very difficult to determine that. Fortunately, duty quality guns have a margin of safety built in.
     
  12. Kingarthurhk

    Kingarthurhk Isaiah 53:4-9

    7,587
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    They're all diffrent. I carry glocks. Another guy carries a sig. Another guy carries a Smith and Wesson M&P. Another guy carries a Berretta Storm. Heck some people still carry a 1911 cocked and locked. Heck some people carry XD's. So, since everyone is different, and I am sure there are some others out there I haven't mentioned. How is that determined?
     
  13. razdog76

    razdog76 Heavy Mettle

    3,620
    1
    Kingarthurhk, I am sure that all of the aforementioned guns have been tested with strain gauges attached to figure out how much pressure will cause them to fail.

    Assuredly, none of them are at the SAAMI pressure spec for any given cartridge they are chambered in. They have to have to be able to handle higher pressures, otherwise they would not be able to survive proof testing in countries that do proof testing.

    Besides that, I believe SAAMI specifications allow 1 in 1000 of a given lot to be high or low.
     

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