Check your lots of Prvi M-193 ammo for problems...

General Firearms Reloading & Ammunition
1

For those of you with lots of Prvi that you might be keeping around for whatever use, you should really check your lots.

In 2008-ish I purchased a couple thousand rounds of Prvi, I wanted to try it out, and it was one of most common ammunitions available at the time.

As I’ve finally gotten around to shooting it, I am getting amazingly poor accuracy. Something in the order of 10 MOA at 50 yards, consistently, in many different weapons. I first noticed this during a rifle match when I couldn’t hit a steel target at 200 yards. It wasn’t that the zero was off that much, more of that my shots were going left, right, over, under… Basically, at 200 yards, I was shooting at a 4 MOA target, my pattern (wasn’t a group) was something in the order of 3-4 feet at 200 yards. I figured it was my gun/optic or something. Switched ammo and suddenly my group size was back to normal, 10/10 on the steel.

Well, I figured my BCM 16" mid-length with the Larue rail just didn’t like that ammo.
Later I tried to zero a new 14.5" carbine with a 1:9 twist barrel with the Prvi. At 50 yards, I was all over, not even able to keep my shots on paper. It was a new gun, so I thought something was wrong with it.

Finally my brain kicked in, and I shot the Prvi ammo in several different guns. These Include:
BCM 16" middy, Larue rail, 1:7 twist
Sabre 16" Middy, Larue Rail 1:7 twist
Sabre 14.5" carbine, 1:9 twist
BCM 14.5" M4, Larue Rail 1:7 twist
FN M16 1:7 twist
BCM 11.5" SBR with Larue Rail 1:7 twist
Sabre 20" 1:7 twist M16A4-ish barrel, larue rail
Sabre 11.5" SBR, Larue Rail, 1:7 twist
Remington 700 PSS with 1:9 twist, 4.5-14x Leupold VX3
Bushmaster 16" frankengun with a 1:9 twist.

Amazingly, in all these weapons, my group sizes were at best 8MOA at 50 yards. I’ve tried shooting farther, but honestly, the groups (patterns) are so large, it really doesn’t show anything, and it’s hard to keep the rounds on paper.

Here is an example of a 50 yard group. I shot this from a sandbagged rest, with a BCM 11.5" SBR, with Larue 7" rail, and an Aimpoint T1. This gun shoots, and I was able to come in overall high shooter in a Pat Rogers/EAG course in 2009 with it, and was the high shooter for the modified MEU(SOC) course Pat ran in a 2010 course with this weapon. I fired 20 rounds of the Prvi at the center of the target. I followed this up with 10 rounds of Hornady Practice 55gr ammo at the head, to show that it isn’t my gun or myself that is screwed up. No fliers were called. I’ve tried this at 100, but I cannot keep the rounds on target. The circle in the center of the target is 8"…

You might think the round that went low right would be a flier. Hahaha. I think of it as proof of the inconsistency of this lot of ammunition.

So, it only took me about 700 rounds, of the 2200 I had to figure out that this stuff shoots horribly. So I contacted the importer TR&Z. After three weeks of correspondence (mostly me asking for answers), These are the answers I was given.

Just received a reply from the factory on the original accuracy test of 5.56x45 M-193 lot 0707-09. Average mean radius for five 10 shot groups was 2.79 cm. ( 1.1 inches ) at 110 yards. Accuracy test was performed in a 12 inch twist barrel. Comparing this figure against MIL-C 9963 which calls for 2.0 inches amr at 200 yards, we see that results are satisfactory.

That may have been possible. Maybe this was from the beginning or ending of a production run. I am 100% sure the rounds I have wouldn’t pass this test. I consider a 5" group at 50 yards lucky at this point. So, when I mentioned again, that there is something wrong with the ammo, and I’d just like it replaced, I get this:

Looks like the ammo is O.K. We cannot replace if the product is not defective even though there appears to be a lack of interfacing between your gun and our ammunition.

So in other words… Their ammo passed their test at factory. Despite the fact it doesn’t work in any of my weapons, it is an issue on my end. Apparently no defect ammo can leave the factory, so if you get any with problems, the problems are yours!

I’m never purchasing Prvi ammunition again, as apparently, it is unsupported in the USA if you have a problem with it. Right now I have 1500 rounds of ammo, From Lot 0707-09, that I don’t know what to do with. All I can say positive, is that it has been reliable, aside from a stuck case in a clean BCM 16" mid-length. I’d sell it, or give it away, but I would consider the ammunition a liability if I actually had to use it for anything other than making sounds. I’m a bit upset that I spent money, time, and energy, shooting, testing, and then to spend three weeks corresponding with TR&Z to be told that it’s my problem. Apparently, I purchased 2200 problems.

So, as an advisory, check your lots of Prvi. Apparently if you find problems, your out of luck. I know many lots of the M-193 shoot well.

Again, this was from Lot 0707-09

I would be very interested if anyone has any rounds of this lot, and what they are getting. I honestly do suspect that I may have gotten a couple cases from a temporary machine glitch or something.

2

Since I only have 400 issue free rounds of Prvi 5.56 through my rifles, my first hand input is menial. However, being a studious member here for a while tells me that this does seem odd since almost everyone prior seems to have had no issue with the ammo.

As you stated FTF’s and FTE’s are different from rounds that can’t seem to hit the broad side of a barn from 50 yards, but you get my point. Sounds like you just got a bad batch.

3

I saw this thread over on ARF. I’m going to check to see what the few boxes of prvi I have are labeled.

4

I shoot a lot of the 62gr and have had no issues at all and found it to be more accurate than the guy behind the trigger. Thanks for the heads up with the lot #'s.

I am surprised that they wont step up and at least test it to determine if it defective.

5

Pure conjecture, but it sounds like an undersized bullet, like maybe a .222 or .223 projectile. Do you have any calipers or a micrometer?

6

Could be… or really bad bullet runout… I wonder if UVvis can see if the bullets look to be seated straight.

7

Interesting. Good idea checking the bullet diameters.

A Prvi bullet I pulled with a kinetic bullet puller is coming in at .225, both above and below the cannelure.

From a box of Hornady 55gr FMJ’s bullets as reloading components, the ten or so I pulled out all came in at .224 (caliper reference check).

Checking another half dozen Prvi bullets from my lot, all .225" immediately above the cannelure/case neck. (not going to pull them all)

Compared to half a dozen Black Hills 55gr FMJ rounds (red box), they are all coming in around .224 right above the case neck. Same as a Black Hills red box 75gr match.

Bullets appear to be seated strait.

Empty brass length is 1.757"

I can’t tell quite how these were crimped, but the crimp looks pretty heavy.

Now I kinda wish I had some Prvi from one of the good lots to try.

Also, while I am rather annoyed with this, I’m trying to get more info from elsewhere.

Maybe I got some with a thicker jacket, and a heavier crimp, or something odd like that.

8

I had the same accuracy problem with my last batch of PPU 55-grain ammo. That was from 2-years ago and I havent’ bought any since.

9

That’s .001" too big, right? Is that enough to make a difference?

If you’re already pulling the bullets, then you might inspect and weigh the powder charges, too. It would be interesting to know how much they vary in weight, and/or if there’s anything obviously irregular about them…

Bimmer

10

You don’t happen to have the lot number do you? Or if you remember about when you purchased it from where? (can pm me that if you don’t want to post)

Dunno. An oversided bullet and heavy crimp could be a bunch of what I’m seeing.

Bimmer, not saving the powder charges. I’ve only pulled two, and I’d need to pull like 10-20 to get a good picture of that.

11

Yes, but even weighing five (or only two!) would give us some kind of idea of whether they’re wildly inconsistent…

Bimmer

12

Ive shot at least 5k rounds of PPU M193, and not had anything out of the ordinary.

My latest lot is: 0903-07

I only have 2 20rd boxes plus some loaded mags left but no issues on my end.

I did buy a couple hundred rounds of the 75GR match ammo, and it would do well to shoot 3" groups at 100 out of a few “match” barrels.

13

I know there are many good lots of Prvi out there. I’m mostly looking to see if anyone else has any from 0707-09, and how it shot, or if anyone has other problem lots.

14

I’ve run about 3500 rnds of PRVI M193 since early 2008. I haven’t experienced any problems with accuracy. I still have about 1500 rnds stored. I will check my lot #s tonight and see what I have. I did order some more earlier this year so I’m not sure if I have anything that old.

FWIW, I haven’t had any failures with the 3500 rnds that went down the pipe.

15

I’ve shot about 1,500 rounds of it without a problem. Consistantly 1.5 - 2 inchs at 50 yds.
I’ll check what I have left to see what the lot numbers are.

Scoby

16

I agree, that’s strange and not consistent with what I’ve seen from Prvi. Sounds like a bad lot like you said. Serbia has been making quality ammo since the 1930s, at least.

17

Prvi Partizan M193 2009

PPU’s M193 clone uses a lead core, copper jacketed 55 grain bullet with a cannelure. The base of the bullet has a deeply “rolled-over edge” design which creates a large hollow in the base of the bullet. Using a Mitutoyo blade micrometer, I measured the diameter of the bearing surface of the bullet. Several measurements gave an average diameter of 0.22415”.

The cartridge case is constructed of brass and displays the annealing iris typically found on military ammunition. The case mouth and bullet have a small amount of asphalt sealant applied. The case mouth is crimped into the bullet cannelure using a collet crimp. The cartridge is charged will “ball” powder and the primers are crimped and sealed. The head stamp reads: “PPU 09 5.56 x 45”. The cartridges come packaged in little “sugar cube” boxes holding twenty rounds apiece.

The U.S. mil-spec accuracy requirement for M193 calls for 10-shot groups of the ammunition to be fired from a machine rested, bolt-actioned test barrel such as those pictured below.

The mil-spec testing is conducted from a distance of 200 yards and the dispersion of the shot-groups is measured using the mean radius. The accuracy spec requires that the average of the mean radii of all the 10-shot groups is not to exceed 2 inches. A mean radius of two inches at 200 yards equates to an extreme spread of approximately 6 inches or 3 minutes of angle.

I performed an accuracy evaluation of Prvi Partizan’s M193 load (lot # 0905-05) following my usual protocol. Shooting was conducted from a concrete bench from a distance of 100 yards (confirmed with a laser range finder.) The test vehicle was a 16” Colt HBAR with chrome-lining, a NATO chamber and a 1:9” twist. This is the barrel found on the Colt 6721 Tactical Carbine. The barrel was free-floated with a LaRue Tactical handguard.

The fore-end of the carbine rested in a Sinclair Windage Benchrest and the butt-stock rode in a Protektor rear-bag. Sighting was accomplished via a Leupold VARI-X III set at 25X magnification and adjusted to be parallax-free at 100 yards. A mirage shade was attached to the objective-bell of the scope. Naturally, the wind conditions were monitored using a Wind Probe. The set-up was very similar to that pictured below.

The Wind Probe.


No animals were harmed during the testing of this ammunition!

A 10-shot control group was fired using match-grade hand-loads topped with Sierra 55 grain BlitzKings. The extreme spread of that group measured 0.89”.

Four 10-shot groups of the Prvi Partizan M193 load were fired in a row. The extreme spreads of those groups measured:

2.73”
5.45”
3.07”
3.74”

for a 10-shot group average extreme spread of 3.75”. The four 10-shot groups were over-layed on each other using RSI Shooting Lab to form a 40-shot composite group. The mean radius of the composite group was 1.08”. For comparison, the 40-shot composite group of PPU M193 is shown below next to a 30-shot composite group of IMI M855 fired from the same barrel.

The 40-shot composite group.

Comparison to IMI M855

The smallest 10-shot group of PPU M193.

18

Molon: Thank you for just an amazing post. Added to the list of reasons M4C is such a great resource and I applaud you for your efforts here.

When I read this thread this morning, I pulled a pack of Privi 55gr M193 to check the lot number. I’m not sure about the structure of Privi as an ammunition company, but it appears at least that they may have more than one plant churning out ammunition, as my boxes are labeled differently. In any case, for what it’s worth - Lot # 0901-01 (also 2008) appears to be just fine.

Thanks again…

19

Thanks Molon!