Page 1 of 2 1 2 LastLast
Results 1 to 10 of 13

Thread: PROOF TESTING

  1. #1
    No Hope For Me 1biggun's Avatar
    Join Date
    Oct 2005
    Posts
    13,236
    Feedback Score
    14 (100%)

    Default PROOF TESTING

    I have been thinking about this for a long time. Im starting to look into what it would tke to see what a standard AK will proof out at.

    I found companys that do it. Im broke but it would be worth knowing undre a controled setting what we can safely build these guns to. I have no idea of the costs.

    Ballistics Testing: Test Guns - Test Weapons - Test Ammo

    Quote Request

  2. #2
    TRX
    TRX is online now
    Gunco Irregular TRX's Avatar
    Join Date
    Aug 2008
    Location
    Central Arkansas
    Posts
    2,542
    Feedback Score
    2 (100%)

    Default

    The strain gauge type pressure testers have really come down in price in the last few years. They just glue to the barrel; no destructive machining required.

    It might still be outside your price range for a onesie, but it's something you could use on more than one gun, or for working up loads where you'd know the pressure instead of guessing, etc.

  3. #3
    Happy Camper hcpookie's Avatar
    Join Date
    Feb 2004
    Location
    Williamsburg, VA
    Posts
    7,647
    Feedback Score
    3 (100%)

    Default

    I saw those too... the ones you glue on, right? The kit I saw had the tester and the software for around $300 or so. DEFINITELY worth the investment with all the things we're doing! Maybe that will be my Christmas wish this year

    FYI, the proof loads for 308, 223, etc. are listed in the US Army Cartridges TM... the one that some surplus dealers sell for $15. Well, I found a copy (on Steve's Pages I think) and uploaded it to my file drive here:


    Technical Manuals - Windows Live

    Pretty strong proof loads for some of them!!! Perhaps this info will help out some of our calculations...

  4. #4
    Happy Camper hcpookie's Avatar
    Join Date
    Feb 2004
    Location
    Williamsburg, VA
    Posts
    7,647
    Feedback Score
    3 (100%)

    Default

    cross-posting from the 308 AK thread:

    http://www.gunco.net/forums/f244/308...3/index25.html

    Quote Originally Posted by Viper Dude View Post
    0.1964 x 63,000 = 12,370.02 lbs force on the bolt face.
    So am I reading that that is 6 tons pressure?

    If that's the reading, then could we not calculate the yield strength per square inch of for example a 4140 steel based on the published specifications on all of the metallurgy websites?

    From that, we can determine how much load the locking lugs endure:

    We need a press that has a gauge readout. My cheap-o doesn't but I know there are presses out there that have an indicator so you know exactly how much you're pressing down.

    Using that we could test the bolt thrust with a trunion and a ram made from hard steel. Set the trunion on end and just press down with the ram until we reach 6 tons. If she holds, then let's repeat the process with whatever pressure calculation the published proof rounds generate.

    PRESTO we have a legitimate answer to whether or not the trunion will work with 308 max pressures. The best part is that we would not need to fire a proof round in the gun to do so - we would be much safer with the trunion on a press.

    Thoughts?

  5. #5
    Gunco Regular allesennogwat's Avatar
    Join Date
    Apr 2005
    Posts
    921
    Feedback Score
    0

    Default

    Proof load firing is done inside a remote shielded device. It has a hood or a cover or a drum completely surrounding the firearm. It's not something you want to do holding it in your hands against or in front of your face.

  6. #6
    Gunco Regular allesennogwat's Avatar
    Join Date
    Apr 2005
    Posts
    921
    Feedback Score
    0

    Default

    Some pics of 30 Carbine proof firing and M14 specs.
    Attached Images Attached Images

  7. #7
    Gunco Regular allesennogwat's Avatar
    Join Date
    Apr 2005
    Posts
    921
    Feedback Score
    0

    Default

    The following are from Frankfort Arsenal Small Arms Ammunition Pamphlet 23-1, July 1967. Each round is designated as "Cartridge, Caliber__, Test, High Pressure, M_.
    1. Caliber 5.56mm, M197, 70,000 plus/minus 3,000 psi., Ord. Part Number D10533839
    2. Caliber .30 Carbine, M18, 47,500 plus/minus 2,500 psi., Ord. Part Number B6176267
    3. Caliber .30, M1, 67,500 psi., Ord. Part Number B6016308
    4. Caliber 7.62mm NATO, M60, 67,500 plus/minus 2,500 psi., Ord. Part Number C7553703
    5. Caliber .45, M1, 22,000 psi., Ord. Part Number C6000502
    6. Caliber .50, M1, 65,000 psi., Ord. Part Number C5544097
    7. Caliber .50, Spotter, T251, 55,000 psi., Ord. Part Number D10534770

  8. #8
    tired of idiots vz58's Avatar
    Join Date
    Sep 2006
    Location
    central NC
    Posts
    2,275
    Feedback Score
    25 (100%)

    Default

    I know of a shop that has a gauge on a HUGH press, it may be too big and the gauge may not work. I will ask tomorrow.

  9. #9
    TRX
    TRX is online now
    Gunco Irregular TRX's Avatar
    Join Date
    Aug 2008
    Location
    Central Arkansas
    Posts
    2,542
    Feedback Score
    2 (100%)

    Default

    I had thought of a press, but would a steady pressure be the equivalent of the shock load of firing?

    Cracks are more likely to form with cyclic loads than steady pressure. I think a lug is more likely to fail from a crack than from just shearing it right off.

  10. #10
    Gunco Regular mrtank's Avatar
    Join Date
    Jan 2008
    Posts
    336
    Feedback Score
    0

    Default

    Real Guns This one looks very nice but they don't sell it any more....

    PressureTrace & Accessories: Recreational Software, Inc.

    The problem with calculating the lug strength on the ak trunnion/bolt is it is a pain. You can't just calculate for the bolt lug area, because not all of the lug has trunnion supporting it. Thing aren't symmetrical, don't what steel it was made out of ect..

    I wonder what this guy would have to say about the matter. Varmint Al's Engineering Page - Finite Element Analysis of Structures

Page 1 of 2 1 2 LastLast

Search tags for this page

There are currently no search engine referrals.
Click on a term to search our site for related topics.

Posting Permissions

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