Not sure if this question can be answered...

Discussion in 'Ammunition & Reloading' started by SRK97, May 21, 2013.

  1. SRK97

    SRK97 Well-Known Member Supporter

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    Is there any type of calculator where you can plug in your powder, bullet weight and barrel length so that you can find the velocity and energy?
     
  2. Anna_Purna

    Anna_Purna New Member

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    if there is, its probably not very accurate, as there are too many variables with crimp, and headspace, etc

    Best thing I'd imagine is to buy a chronograph and learn the math formula.
     

  3. SRK97

    SRK97 Well-Known Member Supporter

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    Any Idea how much a chronograph runs?
     
  4. Anna_Purna

    Anna_Purna New Member

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    Depends on how new the battery is! lol :D
     
  5. Anna_Purna

    Anna_Purna New Member

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    I couldn't help you with what is good or not in Chronographs, but basically 90 dollars and up.

    Hopefully the guys will wake up out of their drunken stupor and chime in.
     
  6. MisterMcCool

    MisterMcCool Well-Known Member Supporter

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    Handloads.com has some ballistics calculators.
     
  7. JonM

    JonM Moderator

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    Thats not a good or safe way to determine the max pressure of a load.

    Bullet construction as in how much bearing surface a bullet has also has an enourmous role in pressure.

    When a powder/bullet maker puts out load data they are using pressure barrels to test with and even that is merely a very rough guidline for the handloader.

    Handloading is called an art because no one has come up with a means of reliably determining what pressure level a given gun can take and then measuring the pressure to any real certainty.

    What we instead do is go off experience by experimentation to find out exactly where guns will blowup then backoff the charge weights combine that with pressure barrels for testing and we end up with lots of known load data we can work from to develop "safe" loads for unknown untested cartridges.

    I would be very hesitant to use any program that claims to tell you what pressure a given load is developing.
     
  8. JimRau

    JimRau Well-Known Member Supporter

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    It is very hard to 'blow up' a rifle. Pistols I have seen go boom several times. I had a friend who was using a Lee loader MANY years ago and he was loading a 270 with the measure for 4831. He was new at loading and not the brightest bulb in the batch so when he ran out of power he went to the local hardware store and ask for some powder. The clerk was not much better than he so when he ask what power he wanted he said it starts with a '4', so he bought 4227!:eek:
    He loaded up 20 rounds with the 4227 using the 4831 (case capacity) measure and we went to the dump one weekend to shoot rats and whatever else we could and he let go with the first round. He was shooting a Remington 721. WELL the gun went flying, he spun around and was on his knees holding his poor shoulder and the bullet left a very visible vapor trail. When we picked up the gun the bolt was locked up. When he told me what he did I told him to send the gun and loads to Remington, which he did. Some time later he got the gun back with a letter for Remington. The bolt face had split and locked the bolt up. They checked the barrel and found it was not damaged. They replaced the bolt and told him the load he had shot in this gun FAR exceed the proof loads they use. They did not return the ammo he sent.:D
    Point is it is VERY hard to destroy a modern bolt action rifle. I have another story about us trying to blow up an old Mauser, but that is for another time.
    Just start at the low end of the manual recommendations and if you have a chronograph use it.;)
     
  9. Overkill0084

    Overkill0084 Active Member

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    Quickload will work from the standpoint of getting you in the ball park with a combination. What little contact I've had with quick load is that it is a really cool way to generate a "best Guess." You can try all sorts of cool and interesting possibilities, but you still only end up with a a starting point from which to begin normal load development.
    Chronographs will clock your loads. You can work out all sorts of math problems from there.
    Just my humble opinion, but I think people spend way too much time hung up on velocity and energy numbers. The fastest, baddest load out there ain't $h!t if it isn't accurate or doesn't otherwise function properly. It's been my observation that the most accurate loads of a given combination are quite often, comfortably under max.
    YMMV.
     
    Last edited: May 22, 2013
  10. willshoum

    willshoum New Member

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    join the Marines, enter sniper school...........You become the calculator................
     
  11. mseric

    mseric New Member

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    Lets take a look at a little computer generated QL data.

    In this example I used the old 30-06 with 180gr Sierra and IMR 4350.

    Here is tested data from Hodgdon's web site.

    Code:
    180 GR. SIE SPBT 	IMR 	IMR 4350 	.308" 	3.300" 	53.0 	2586 	48,300 PSI [B]	56.5C 	2752 	57,200 PSI[/B]   
    Plugging the same components as Hodgdon into QL, we get this data.

    Code:
     Cartridge          : .30-06 Spring.  (SAAMI)
    Bullet             : .308, 180, Sierra SPBT 2160
    Cartridge O.A.L. L6: 3.300 inch or 83.82 mm
    Barrel Length      : 24.0 inch or 609.6 mm
    Powder             : IMR 4350
    
    Predicted data by increasing and decreasing the given charge,
    incremented in steps of 2.0% of nominal charge.
    CAUTION: Figures exceed maximum and minimum recommended loads !
    
    Step    Fill. Charge   Vel.  Energy   Pmax   Pmuz  Prop.Burnt B_Time
     %       %    Grains   fps   ft.lbs    psi    psi      %        ms
    
    -20.0   83    45.20   2263    2046   30467   7728     90.4    1.564
    -18.0   85    46.33   2318    2147   32476   7969     91.6    1.523
    -16.0   87    47.46   2373    2250   34617   8202     92.7    1.483
    -14.0   89    48.59   2428    2356   36901   8426     93.8    1.444
    -12.0   91    49.72   2483    2464   39337   8641     94.7    1.401
    -10.0   93    50.85   2538    2575   41937   8846     95.6    1.360
    -08.0   95    51.98   2593    2687   44714   9039     96.5    1.320
    -06.0   97    53.11   2648    2802   47682   9221     97.2    1.282
    -04.0   99    54.24   2702    2919   50855   9389     97.9    1.246
    -02.0  102    55.37   2757    3037   54250   9545     98.4    1.210  ! Near Maximum !
    [B]+00.0  104    56.50   2811    3158   57887   9685     98.9    1.176  ! Near Maximum ![/B]
    +02.0  106    57.63   2865    3280   61751   9811     99.3    1.143  !DANGEROUS LOAD-DO NOT USE!
    +04.0  108    58.76   2919    3404   65879   9921     99.6    1.112  !DANGEROUS LOAD-DO NOT USE!
    +06.0  110    59.89   2972    3530   70300  10014     99.8    1.081  !DANGEROUS LOAD-DO NOT USE!
    +08.0  112    61.02   3025    3657   75041  10090    100.0    1.052  !DANGEROUS LOAD-DO NOT USE!
    +10.0  114    62.15   3078    3786   80130  10149    100.0    1.023  !DANGEROUS LOAD-DO NOT USE!
    
    Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
    Data for burning rate increased by 10% relative to nominal value:
    +Ba    104    56.50   2932    3435   69272   9382    100.0    1.094  !DANGEROUS LOAD-DO NOT USE!
    Data for burning rate decreased by 10% relative to nominal value:
    -Ba    104    56.50   2643    2792   47088   9494     93.6    1.285
     
    Note how close QL generated data is to actual tested data.

    All this is very cool and a great tool for the handloader, but it is not a substitute for actual tested data when working up loads. Helpful, you bet, substitute not so much.
     
  12. JonM

    JonM Moderator

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    its hard to kaboom a bolt gun its easy to kaboom a semi-auto
     
  13. JimRau

    JimRau Well-Known Member Supporter

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    'Easy' is a relative term. I would be 'easier' to destroy a rifle with an action not as strong as the bolt action, but still you would have to do it intentionally. We placed 'hot rounds' in the ammo caches in RVN to destroy AK's and SKS's as well as some mortars. I did not get to examine any of these rounds in detail but was told they were loaded with 'demolition' material (RDX based), not smokeless powder. I am curious what would've happened to a 740 if the 270 rounds described above would have been fired in it!:eek:
    It would not have been good!;)
     
  14. locutus

    locutus Well-Known Member Supporter

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    You can get pretty decent chronographs under $150.

    www.midwayusa.com

    Not as nice as an Oehler but very serviceable