Ammunition Consistency Testing: 5.56 55gr, Winchester White Box vs. Independence

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I fully admit to being a complete and utter nerd. Which explains why the very first thing that went through my mind when I realized I didn’t have anything planned for this past weekend was “Oh sweet! I can go chronograph some ammo!” Some of you may remember my ongoing series where I chronograph commercial ammunition to see which ones are the most consistent. Thanks to the now plentiful supplies I’m finding at local gun stores here in south Texas, I can continue my research. Well, shall we? . . .

Here’s a quick reminder of what’s going on: we run 20 rounds of each brand through a chrony and look at the IQR or InterQuartile Range to get an idea of how tight the group is going to be downrange. There are plenty of other factors in accuracy, but velocity is the only one that’s “clean” enough to calculate and compare (as everything else can be influenced by the shooter, equipment, etc.). For the full methodology check out this article. Just remember LOW=GOOD and we’ll be on the same page.

You may notice that I’ve changed guns again, and I’m doing this on purpose. Some of you have expressed a concern that changing certain environmental variables (the gun, humidity, air pressure, etc) have an impact on the results we’re measuring here. Every time I run one of these tests, I run another 10 rounds of my personal (and ever dwindling) stock of XM193F through the chrono first. This is the same cache of ammo that I used for the very first test, coming from the same lot number, and even from the very same case.

I’m down to my last three boxes, but it’s the same ammo. And every time, the interquartile range of the velocity comes back the exact same. In other words, none of the external factors matter. The velocities absolutely do change — up or down — depending on external factors. We’re comparing this ammo to itself in identical conditions for the entire run. The velocity changes, but the IQR remains the same. Now, on with the test.

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First up is the Winchester 55gr 5.56 ammunition that was generously donated by Winchester to help me practice for the competition shooting season. This is the exact same stuff that you can find by the crateload in your local Walmart or big box store, relatively cheap and (at one time) readily available.

Caveat: testing this ammunition from one of my sponsors presents a definite conflict of interest. But because this test is based on calculated figures and ends in a repeatable and verifiable result, I’m okay with going forward. In short, there really isn’t any way for me to skew the results.

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The challenger is a brand of ammunition that American shooters have become more familiar with as the ammo shortage has continued: Independence Ammunition. Manufactured in the land of RF’s favorite supermodels and armed schoolteachers (Israel), this imported ammo has often been the only brand available for purchase due to the large quantity that has suddenly appeared on our shores. Available and cheap, the ammo seems to be a welcome change from the overpriced and unavailable name brand ammo. But is it any good?

Just for fun, I once again did a chrony comparison of 5.56 ammo both with and without a silencer. Here’s the boxplot without any normalization (and comparing to the current leader):

55gr

There it is again — the velocity of the ammunition increases slightly with the addition of a silencer. Then again, on the SCAR, there’s an adjustable gas port that you tune to adjust for the increased back pressure with a can. It’s possible that the smaller gas port might account for the higher velocity, but seeing as the gas is still trapped (unlike the AR-15’s open gas system) it’s not likely to have this level of an impact on the velocity. Cool, huh?

And here’s the normalized plot:

55grNorm

The IQR of the “suppressed” Winchester rounds was a bit off, but to be expected since I only fired around 10 rounds instead of the full 20. Speaking of being off, the Independence ammunition not only had a huge IQR but also had the biggest whiskers of any ammo I’ve tested so far. That indicates even more inconsistency in the ammunition than we usually capture with the IQR calculations.

So, what’s the final word? How do these stack up against the other ammo we’ve tested?

55grFull

What I find interesting is that the IQR for the 55gr version of Winchester’s 5.56 ammo matches up almost exactly with the IQR of their 64gr variety. That 64gr test, by the way, was conducted in a completely different climate with a completely different firearm. In fact, it was the first test we ever did. So, (A) nice to see some validation for our assumptions and (B) interesting that ammunition from the same factory and of the same price range is roughly equally consistent.

Here are the latest charts. Keep in mind that prices reflect the actual price per round at the time the ammunition was reviewed. I’ll be going back through and re-researching all the ammo again shortly, as soon as things calm down a bit more. Stay tuned, I’ll have some more .308 ammo coming up later this week!

Brand and Weight Caliber IQR $/round
Winchester / Olin M855
62gr Penetrator
.223 Rem 9 $0.50
Wilson Combat
77gr Sierra HPBT Match
.223 Rem 19 $1.52
Wilson Combat
65gr Sierra SP BT
.223 Rem 21 $1.52
Hornady Steel Match
75gr BTHP Match
.223 Rem 25 $0.44
Hornady
75gr BTHP Match
.223 Rem 29 $0.79
CorBon
69gr HPBT
.223 Rem 30 $1.18
Remington Premier Match
77gr BTHP
.223 Rem 36 $1.50
Winchester
64gr “Power Point” SP
.223 Rem 38 $0.82
Wolf
55gr FMJ
.223 Rem 40 $0.21
Federal XM193F
55gr FMJ
.223 Rem 40 $0.32
Winchester
55gr FMJ
5.56×45 40 $0.50
Pierce
55gr HP-BT
.223 Rem 42 $?.??
HPR
75gr BTHP Match
.223 Rem 43 $0.50
Nosler Varmint
40gr Ballistic Tip
.223 Rem 44 $0.86
Handloads – 20.8gr N-135
75gr Hornady HPBT Match
.223 Rem 49 $?.??
Handloads – 21gr IMR 3031
75gr Hornady HPBT Match
.223 Rem 52 $?.??
Winchester PDX-1
60gr SC-HP
.223 Rem 58 $1.45
Freedom Munitions
55gr FMJ-BT
.223 Rem 66 $0.42
American Eagle
55gr FMJ-BT
.223 Rem 68 $0.30
Independence .223 Rem 69 $0.50
Brand and Weight Caliber IQR $/round
Remington UMC 115gr .300 BLK 20 $0.52
Remington AccuTip Premier 125gr .300 BLK 20 $1.39
CMMG 147gr .300 BLK 26 $0.78
Remington Subsonic 220gr .300 BLK 27 $0.92
PNW M 155gr .300 BLK 28 $0.90
PNW D 220gr .300 BLK 54 $1.08
Brand and Weight Caliber IQR $/round
Hornady Superformance Match
150gr SST
.308 Win 26 $1.21
Wilson Combat
168gr Sierra HPBT Match
.308 Win 28 $1.99
PMC Bronze
147gr FMJ BT
.308 Win 39 $0.50
SetPoint – 44gr Varget
150gr Hornady FMJ BT
.308 Win 52 $1.74
Prvi Partizan
150gr FMJ
.308 Win 54 $0.82
Remington “Managed Recoil”
125gr CORE-LOKT PSP
.308 Win 125 $1.40

comments

  1. avatar Aharon says:

    The .38 Special ammo that I own from Independence was manufactured in Lewiston Idaho which the same small town where CCI is based. Federal Ammo’s parent firm HQ’d in Minnesota owns Independence Ammo, Federal, CCI, and other recognizable brand names.

  2. avatar Human Being says:

    Finally! Glad to see this series continue.

    1. avatar M109 says:

      Love to see this going on. I am however disappointed with the findings of the Israeli made Independence branded 5.56. I honestly expected very good consistency, but oh well.

  3. avatar Anonymous says:

    “Ammunition Consistency Testing: 5.56 55gr, Winchester White Box vs. Independence”

    Because that’s all they could find at that moment.

  4. avatar AlphaGeek says:

    Pretty sure Winchester’s parent company is Olin, not Odin. Autocorrect FTW?

    1. avatar Aharon says:

      I think Winchester firearms and Winchester Olin the Ammo folks are independently owned unrelated companies. Winchester the gun maker is owned by the same people who own Browning namely FN Herstal.

      1. avatar AlphaGeek says:

        Correct. I was referring to the ammo makers, members of the ATK gov-industrial megaplex.

    2. avatar Gyufygy says:

      Norse gods need to diversify to survive these days.

      1. avatar Human Being says:

        You must have read the most recent Dresden Files book.

        1. avatar A-Rod says:

          Hell yeah, glad there is another Dresden fan here. The last two books got me looking for another lever action than just my Henry .22. Book 15 cannot get here soon enough.

        2. avatar Human Being says:

          “Then what is Summer’s purpose?”

          Only Harry Dresden would take on Santa Claus with a .45 Colt carbine.

        3. avatar Gyufygy says:

          Wasn’t directly referring to that, but yes, Dresden is awesome. Definitely agree on his Awesome Moment of Badassness and wanting a lever gun. 😀

    3. avatar Odin says:

      you rang?

  5. avatar CharlieKilo says:

    Out of curiosity, what’s the twist on that barrel? (Rhetorical for me).

    1. avatar Nick Leghorn says:

      1:7 in the SCAR.

  6. avatar Tommy Knocker says:

    Did I miss what chronograph you used?

    1. avatar Nick Leghorn says:

      Shooting Chrony, the F1 style.

  7. avatar Dave J says:

    Any barrel cleaning or cooling time between each brand?

    1. avatar Nick Leghorn says:

      Nope.

      A) It’s a SCAR and don’t require none of that city-slicker cleaning.

      B) Since we’re comparing the ammunition to itself, it doesn’t impact the accuracy of the results. It should definitely have an impact on the velocity, but not the IQR. That’s the wonder of a calculated metric.

  8. avatar Shenandoah says:

    Any chance there’s a ballistic gel test in the offing comparing different 5.56 loads with 7.62×39, maybe throw .300 BLK in there too?

  9. avatar UcsbKevin says:

    if only those prices were still real….

  10. avatar Don says:

    This is awesome Nick!

    Could you add to this handloaded ammo with individually weighed powder charges?

    Also some kind of control test to make sure that barrel temperature didn’t affect the results.

    I don’t know if barrel cleaning would be as important so long as you didn’t start with a totally clean and oiled barrel. Like if you started with a cleaned and oiled barrel and then blasted 30 rounds of something to get some “baseline” barrel dirt you’d probably be ok.

    A related test would be to fire rounds at regular intervals, like one round every 2-5 seconds starting with a clean and cold barrel. Do this for about 100 rounds. Then compute your variances using a sliding window across the shot sequence. For example with a window of size 11 rounds, starting with round 6, compute statistics for rounds 1-11, then for round 7 compute statistics for round 2-12, and so on until the end. This would test the affect of both dirt and heat build up. If you really wanted to go all out put a thermocouple on the barrel and record the temperate on each shot.

    Doing the same test except letting the barrel cool in between shots would let you just test “dirt”. Using this “dirt” data and the “dirt+heat” data you could decouple the contributions of “dirt” and “heat”. (Since you can’t test “heat” without “dirt” easily).

  11. “Just remember LOW=GOOD”

    Let’s put some of this in perspective.

    Take some of that “bad” ammo, the Independence 55. You report a range of 3125-3300. Now let’s ask what happens if you have one round at 3125, the next at 3300, all else equal, using a ballistics computer. At 100 yards, the 3300 should hit 0.1″ higher than the 3125. At 200 yards, the 3300 should theoretically hit 0.5″ higher than the 3125. At 600, 12.6″

    Certainly it is not choice ammo (aside from the relatively light bullet, but that’s a wind issue) for long range work. But for most 100-200 yard applications, I would think it is just fine and no plinker or anybody whose competition target is generous should snub their nose at it.

    (Now, it is possible that whatever is causing the velocity inconsistency (powder charge, seating depth, case volumes, etc…) could cause the group to open aside from theoretical vertical stringing. )

    I’m just not a fan of paying for more accuracy than is really necessary, and cringe when others do.

    I’m not saying your test doesn’t identify who makes the more consistent ammo, I’m just saying that there is probably only a very small group of shooters for whom the difference is worth considering when buying.

    1. avatar Citizen says:

      Thank you for breaking this down for those of us who didn’t understand what the ballistics numbers meant in real-world terms. I just bought a couple of boxes for plinking, since I’m not hitting anything like 600 yards anywho.

  12. avatar Eric says:

    Hey. I recognize that range. My personal favorite place to shoot.

    Best of the West Shooting Sports

  13. avatar A-Rod says:

    Side question- I know about the Wylde chambering from RRA in the 5.56/.223 calibre but is 5.56/.223 issue the same for bolt action rifles?

  14. avatar A-Rod says:

    I know about the Wylde chambering from RRA in the 5.56/.223 calibre but is 5.56/.223 issue the same for bolt action rifles?

  15. avatar bluegreen says:

    CRAN-R

  16. avatar JW says:

    Ah… The sweet smell of real empirical data! Looks like I will “Have too” purchase a chronograph just to validate the results.

  17. avatar Ensitue says:

    There is still NO ammo available localy

  18. avatar Eschlo says:

    I know it’s been a while for this thread, but I’m a noob that was looking for Ballistics data on Independence 5.56 (the only 5.56 ammo I could find locally) in hopes of assigning a reasonably close profile into my Bushnell Scout 1000 ARC rangefinder (it suggests drop compensation in inches for common factory rounds based on range and angle). I see now I may have the wrong round for any long range shots.
    Three questions:
    1) If I’m reading your data correctly, Independence 5.56 has a very high IQR and is thus VERY INCONSISTENT at long range?

    2) Based on your tests does the Winchester / Olin M855 62gr Penetrator have the most predictable point of impact on follow up shots?

    3) Is that the same round that I commonly see referred to as 62gr “green tip” penetrator available in bulk and manufactured by Lake City or Federal?

    If it matters, I am using a Ruger SR-556 Piston AR with a 16″ barrel and 1:9 twist.
    Thanks in advance… like I said, I’m fairly new to outdoor rifle shooting.

    1. avatar Matt in FL says:

      1) Well, a high IQR isn’t a guarantee of high inconsistency at long range (what’s long range?), but it’s a good indicator. If you had a large spread of value, but most were clustered around a single point, then you’d have a large spread, but a low IQR. The larger the IQR, the larger the variation in velocity. Ideally you want a small range, with an even smaller IQR, like you see for M855 in the graphs above, meaning it’s going to do “X”, and nearly exactly “X” every time, except in cases of extreme outliers, which are rare.

      2) With everything else being equal, the most consistent velocity should have the most consistent point of impact. But that’s removing all other influences, such as QC in bullet production, heating of the barrel, etc. All you’re guaranteed is that the bullets are leaving the gun at nearly the same speed, as measured 10-15′ out from the muzzle. If the bullets themselves have issues, that effect won’t be felt ’til much further downrange.

      3) M855 and “green tip” are interchangeable terms for the steel core penetrator round. However, no, the Winchester/Olin is not the “same round.” Lake City is run by ATK/Federal. Winchester could manufacture an identical round and call it M855, but it would not be “Lake City” M855, it would be Winchester M855.

  19. avatar old air force says:

    Just found this thread today after a trip to the range a couple of days ago. I had the chrony with me and did my own test on Independance 5.56. Two guns. 20 rounds each. Gun one, White Oak Varmit upper 1 in 8 24 inch bull barrel. The slowest was 3569 fps. and the fastest was 3612. The avg. was 3592. Not to bad on accuacy either but I only had 100 yds and was working on scope adjustment. Gun two, Bravo Company 20 inch goverment profile with 1 in7 twist. Slowest was 3364 and the highest was 3411. The average was 3390. Accuracy was decent with iron sights as well. I will use it more often for general rounds as it performed well and I keep the brass.

  20. avatar Nick says:

    I’d like to see a test on the ZQ1 distributed MKE 5.56x45mm 62gr ammo, sold by walmart.

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