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    Prvi Partizan 75 grain Match Ammunition: Accuracy, Velocity and Terminal Ballistics

    Prvi Partizan 75 grain Match Ammunition.





    The Prvi Partizan 75 grain match ammunition uses an open-tip-match bullet very similar in configuration to Hornady’s 75 grain BTHP bullet used in Hornady’s TAP line of ammunition and in Black Hills’ 75 grain MHP line of ammunition. The Prvi Partizan (PPU) bullet has a nominal length that runs approximately 0.010” – 0.015” shorter than the Hornady bullet. The PPU 75 grain bullet does not have a cannelure, but the case mouth on this load does have a slight collet crimp on it which puts a slight crease in the bullet.















    The PPU 75 grain match load uses Boxer primed brass cases and is charged with “ball” powder. Neither the primer nor the case mouth have sealant and the primer is not crimped. Previous chronographing of this load through multiple barrel lengths shows it to run an average of 127 fps slower than the Black Hills 75 grain MHP load.

















    I have read some statements that claim the PPU 75 grain bullet was designed to shoot well through 1:9” twist barrels, yet none of those making these statements have provided any scientific evidence to support this claim. From a 1:9” twist barrel, the PPU 75 grain match bullet has a gyroscopic stability factor (GSF) of less than 1.25 for all velocities.




    Gyroscopc stability factor from a 1:9" twist barrel.






    Gyroscopic stability factor from a 1:7.7" twist barrel.






    The test-vehicle for this evaluation was an AR-15 with a 24” stainless-steel Kreiger VarMatch barrel, with a 1:7.7” twist, installed on a LaRue Tactical Stealth upper receiver. A Leupold Competition Series Scope was used for sighting. No malfunctions of any kind were experienced during testing.









    Following my usual protocol for accuracy evaluation, shooting was done from a bench-rest at 100 yards. Three 10-shot groups were obtained using the PPU 75 grain match load. Those three groups had extreme spreads that measured:

    0.66”
    0.92”
    1.14”

    for an average extreme spread of 0.91”.



    The best 10-shot group from 100 yards.






    The three groups from above were overlayd on each other using ]RSI Shooting Lab to obtain a 30-shot composite group. The mean radius of this composite group was 0.29”. For comparison, this composite group is pictured below next to a composite group of the Black Hills 75 grain red box MHP load as well as a composite group of one of my handloads.









    Chronograph Data for Prvi Partizan 75 grain Match ammunition.









    Prvi Partizan 75 grain Match; Velocity Update


    Here's a little update on the velocity aspect of the PPU 75 grain Match load. One can't help but wonder if Prvi Partizan has been listening to its customers. About the only complaint anyone has had with this load is that it has a lower muzzle velocity than the Hornady or Black Hills 75 grain loads. I recently chronographed the latest lot of the PPU 75 grain Match load that I have on hand and from a 20" Colt A2 barrel it is running approximately 117 fps faster than the original lots of this ammo that I chronographed!









    Terminal Ballistic Properties of Prvi Partizan 75 grain OTM



    Thanks to the efforts of the esteemed Dr. G.K. Roberts, we now have some excellent information on the terminal ballistic properties of the Prvi Partizan 75 grain OTM load. The same lot of Prvi Partizan 75 grain OTM ammunition that Dr. Roberts used in testing had a nearly identical velocity when I chronographed it from a 16" Colt barrel as noted above.



    Privi Partizan 75 gr OTM

    Velocity: 2468 fps from a 16" 1:7” twist barrel

    penetration in bare ballistic gel: 12.6"

    neck length: 0.8”

    maximum temporary cavity: 3.2” at a depth of 4.7”

    recovered diameter: 0.36”

    recovered length: 0.15”

    recovered weight: 30.1gr

    percentage of fragmentation: 60%




    .....
    Last edited by Molon; 22 November 2015 at 08:38.

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