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 recently 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.  According to the Greenhill formula, the optimal twist for the PPU 75 grain bullet is 1:7.6”.  

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”

1.14”

0.92”

for an average extreme spread of 0.91”.  The three 10-shot groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group.  The mean radius for the 30 shot composite group was 0.29".

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.









Here is a repost of some of the chronograph data for the Prvi Partizan 75 grain Match load.

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%




The “ballistic neck” length or initial upset depth is a critical component in evaluating the terminal ballistic properties of a round of ammunition.  It is the length that the bullet travels in the body before it begins to upset (expand, yaw/fragment.)  Keep in mind that on an average adult male, the surface of the heart is roughly 1.5” below the surface of the chest.  Basically, the shorter the ballistic neck, the better.



courtesy of DocGKR












The difference between a round with a long ballistic neck and a short ballistic neck can be the difference between the bullet sailing through the target without having expanded/yawed/fragmented and only creating the “ice pick” wound versus a bullet that yaws, fragments and creates a large temporary cavity with large amounts of tissue damage within the target.


This . . .



versus this.




This . . .



versus this.


courtesy of DocGKR

Awesome report as usual sir!  Thank you!

I'm glad you reposted. I was looking for this yesterday.

Nice touch with pics of actual cadaver thorax.  Took me a while to figure out what that was.

  Hell yeah, Thanks!

Nice, thank you as always Molon

looking good.  i might pick up a box or two to try out in my 18" stealth.

Nice.  I just ordered a coupld hundred rounds of this.  Looks like i'll be ordering a couple hundred more!

Who has it?

THANK YOU for your considerable time and effort.  I got 5 boxes for XMAS.

Excellent post. Looks like I will be loading some new weight bullets soon.

Dont waste your money

Why do you say this vicious_cb?

I would get the 69gr instead. The 75grs did not shoot well.

Care to elaborate?

My Noveske N4 is licking her chops.

Here is part of the PPU review.  The rest......

Hornady 5.56 TAP versus TAP FPD Page 11

Hornady 5.56 TAP versus TAP FPD Page 13

Well acording to the data posted in THIS thread you are wrong.

Yes and what barrel was Molon doing his accuracy eval from?

Maybe I should have specified the prvi 75gr did not shoot well in the larue/lothar walther barrel. I was getting ~1.5 MOA 10-shot groups.

My accuracy eval is somewhere in the Molon's internet commando 3-shot group thread.

Found it. http://www.ar15.com/forums/topic.html?b=3&f=118&t=279218&page=15

Did you ever figure out was was causing the vertical stringing?

1.5MOA 10-shot groups with eastern-european mass-produced ammo and a semi-automatic rifle is STELLAR performance, and I don't care who you are or what rifle you're using.

I'm thinking pretty much the same thing.  While I usually require MOA to be satisfied with my hunting rigs, At the distances I would be hunting with a 223 round, I would consider 1.5 MOA adequate.  For SHTF self defense ammo, I would think it's far superior to most other "budget" rounds.  After all, these are basically half the cost of TAP Ammo.

I'd daresay that most hunting rifles won't hold 1.5-MOA 10-shot groups without handloaded ammo and aftermarket barrels. Mine won't.

Mine will, but not with all ammo.  I do have nicer than average factory rifles.  With some ammo I can see my groups going well over 2 MOA, but I use those just for fun.  When I purchased my 270, I bought 10-12 different rounds to shoot.  I still have 5 or 6 pieces of boxes of ammo sitting around that my gun doesn't "like".  I've found even lot numbers of the came ammo can make a difference.  When I find factory ammo that my rifles like, I go back and buy all the store has.  I save the ammo each gun likes the best for hunting.  We practice with the rest.  My son is set with 243 ammo for years (no thanks to walmarts 6 box per trip limit).

To quote Rick Jamison,

"After using this machine rest for several years, I have determined that a 1.5-inch 10-shot group at 100 yards... is a good one."

Have you tried the Prvi in your N4?

My RRA 16in 1x8 loves this stuff.  

I've used it for a coyote round when I'm calling, its very effective.

Is the lack of a cannelure anything to be concerned about? I've had setback issues with older Federal Match and older non-cannelured Hornady TAP, but I have no idea how those two rounds were crimped. Judging by this pic, this older TAP I had problems with lacked the collet crimped crease that Molon indicated:


Can I safely assume that I'm comparing apples to oranges?

PPU 75 is collet crimped, there is also a crease on the body bullet.

I will add my experience, which is that in my one AR (self-built on a MUR upper and Noveske stainless 1-7 twist Recce 16" barrel using a TA01 ACOG as primary sight) I can consistently shoot ~1.5 MOA  10-shot groups with the PPU 75gr off a bipod. I just discovered "loading the bipod" so maybe I'll be able to tighten my groups up a bit.

I am on my second thousand round case of this ammo.

Got a chance to get some of the Privi out that I have today.

1.886 MOA 10 shot:



With 16" BCM mounted with a Nightforce 1-4x, off a bi-pod, 100 yards:



Conditions, over cast 0 wind, 58 deg.


I shot 4 10 shot groups that one was the best. One was a cold bore group shot with the gas system turned off (Noveskie Switch Block) I wanted to do a POI comparison. Group shown is 2nd group shot, 3rd group was downright horrid, 4th group was actually very nice with 2 rushed shots tossing the group into the 2.5 moa area.

Over all, I'm happy, I hoped for better but 2 moa from Eastern Europe ammo I can live with.

Molon I have a N4 Noveskie 14.5" I'll try to get out this week with it and the Privi and report back. When I do that I'll reshot the BCM with Black Hills 77 grn match and report back.

Sweet!

Very interesting data. Thanks

JoshAR-

Do you perhaps have a higher mag scope?  4x doesn't seem the best for accuracy testing.



I could just be splitting hairs though. . .

accuracy testing with a 4x scope speaks more to the skill of the shooter than the accuracy of the rifle and ammo in my opinion.  I personally prefer at least 6x for 100 yards.

 

While certainly not the ideal choice for accuracy testing, don't underestimate what can be accomplished with a quality 4X scope.  The 10-shot group pictured below was fired from 100 yards using a Short Dot LE set at 4X magnification.

I completely agree with you Molon.  My primary setup for medium game and such (in both 5.56 and 6.8) is a 1-4x scope.  I can easily harvest deer/hogs out to 200+ yards with them...

tag

Actualy picking up something in 10x or more just for load testing IS on my list of things to do, but it's down a ways.

What I use is Stick and See's that are 2" The "dot" in the NF is 2 MOA, cover breath shoot measure.

I'll shoot again Friday with my N4 and we'll see how I do with a T-1 Aimpoint

One more set same gun as above. Sorry guys I did not get my N4 out.

Black Hills 77grn vs Privi 75 grn Match:

Got out today again. 48 deg, some light rain, light wind blowing down range.

Privi 75 grn 10 shot group, first group of the day:

1.776 MOA





Shifted to 77grn Black Hills Blue box 10 shot.

This group looks worse than it is.

1.887 MOA





Conclusion:

I honestly think I am bouncing off my limits with this gun and it's set up with 4x magnification. Looks like I am pretty constantly in the 1.75-2 MOA range. Privi for me looks like tighter more consistent groups over the BH's. I'll redo more group testing when I have something n the 10x-14x magnification range to work with.

Quick question Josh, which barrel do you have on your BCM?

BFH 16" mid-length with a Noveske switch block for a gas block, a Blackout flash suppressor and SWS free float rail.

Maybe I missed it, but are the groups pictured fired with  or without the suppressor?

Stand by for pics of Prvi's crappy new crimp job on Match 69 and 75 grain. I think this is the cause of my accuracy problems with this ammo. '09 and '10 lots.

Anyone get a chance to try some of the new "blue box" stuff? Is it as good as the old green box?

...aaaand I'm in.

'splitting hairs' in a scope discussion? And I'm the only one who caught that pun?

But seriously, folks, it is very hard to shoot well at 100 with a 4x. Molon's orange target represents just about the best shooting you're going to see with a 4x at 100.