Can you tell which 30 cases were the lead free primers?  We did mostly 10 shot groups this time, with 3 different bullets, and 3 different loads to find more correlations about primer brand affecting accuracy.   Long story short, we think primer does affect accuracy by measurable amount.
On to the testing...  ALL TESTS ARE AT 10 YARDS
Test parameters...
  • 10 Yards distance
  • The brass was weighed to be within .02 grains of each other
  • The brass was then measured to have very similar case capacity within .04 grains
  • The brass all had same length
  • Powder load precision using Gempro 250
  • BULLETS & POWDER LOADS
  1. Berry's 124 Grain HBRN (Hollow base, round nose, thick plating) 
  2. Speer 124 Grain TMJ (Total Metal Jacket) Plated, but looks like Jacket
  3. Winchester 124 FMJ Flat Base
  1.  4.1 Grains Alliant Sport Pistol  (Berry's)
  2.  4.2 Grains Alliant Sport Pistol  (Speer)
  3.  4.3 Grains Alliant Sport Pistol  (Winchester)
This testing method allows us to directly compare 3 different bullet types versus one another as well as primer differences. 
CCI #500
Sport Pistol 4.1, Berry's
~4 out of main group.
CCI #500
Sport Pistol 4.2, Speer
~3 out of main group? Bullet perhaps?
CCI #500
Sport Pistol 4.3, Winchester
Pretty consistent
Loads
3 Top rows is CCI
Fiocchi ZetaPi Primer
Sport Pistol 4.1, Berry's
We are definitly on to something..
Fiocchi ZetaPi Primer
Sport Pistol 4.2, Speer
We shot extra shot at this target, we X'd
Fiocchi ZetaPi Primer
Sport Pistol 4.3, Winchester
We are on to something...
Loads
3 clean rows...thats ZetaPi
Federal Gold Medal Primer
Sport Pistol 4.1, Berry's
~3 out of the main group of 7.  Probably bullet consistency
Federal Gold Medal Primer
Sport Pistol 4.2, Speer
2 flyers.  Group is tight, probably bullet consistency
Federal Gold Medal Primer
Sport Pistol 4.3, Winchester
lights out group...
Loads
3 full bot rows are Federal Gold Medal
Fiocchi Small Pistol Primer
Sport Pistol 4.1, Berry's
Fiocchi Small Pistol Primer
Sport Pistol 4.2, Speer
Fiocchi Small Pistol Primer
Sport Pistol 4.3, Winchester
lights out load...Ridiculous actually, for 10 shots.  Look at bullet, bottom is exposed lead.
Fiocchi Small Pistol Primer
IMR SR4756 6.2-6.3 All metered, nothing measured precision, using totally mixed brass
Grouped by Powder Load
The actual size of the groups, counting every bullet, we believe doesn't tell the story.  As we have said many times, if you shoot 100 bullets, and 99 of them are in a group the size of a dime, then the 100th bullet is 2" out, making a ~2" group, is that a 2" group?  It is a 2" group.  However, the story is that 99 shots went through almost the same hole so that is one accurate load.  Its not possible to understand exactly why that 100th shot was 2" off.  Too many factors.

The overall lesson from this is that the Winchester Bullet is far more accurate overall than the others.  
The other lesson is that we think the Federal Gold Medal Match is the "winner".  This is because the vast majority of the shots hit the same tiny area.  The dispersion of the main group was tighter.    CCI was behind Federal Gold Medal, and ZetaPi is definitely 3rd place.  We did not include the Fiocchi small pistol primer tests, because those were only 6 shots, not 10 like the top 3.  We just included them.  The IMR 4756 is our plinking load, so we included it. 

Our ultimate conclusion is simple after studying all this.  Primer BRAND DOES MATTER, and incrementally affects accuracy.  There is no question the Lead Free Primer was not as accurate and consistent as the traditional primers.  An example is the Berry's group, almost every shot of the 10 hit a totally different spot.







Grouped by Primer Brand...
Now things come into view a little better with this view.  Check the standard deviation column there, next to charge weight.  Notice that the CCI and the Federal averaged "3" SD, but the regular Fiocchi was average neaer ~5, thus near 50%+ more SD.  Then we look at the Lead Free ZetaPi and it has over DOUBLE the standard deviation of the CCI and Federal.
So folks, what we think your buying with primer brands is "consistency".  And it shows in the results.  CCI and Federal are premium brands.  Anyone dispute that?  Fiocchi is a budget/value brand.  HOWEVER, Fiocchi has the ZetaPi lead free out more widespread that other brands, earlier, so we applaud them, and as you see from how clean everything is, they do wonders to keep the gun cleaner + less heavy metals in air to breath.  We like these A LOT.

We conclude these Lead Free are not as accurate as the CCI or Federal, as they are less consistent.   We think this is a guess of a different in accuracy at 10 yards, like all these tests of about 1/3-1/2 inch in accuracy.  So around 1" at 25 yards probably.  Thats not a big deal for 99.8% of shooters.

And what do you want to bet these loads with these Lead Free are on par with PREMIUM commercial bought loads?

I hope you all enjoyed these tests, please support us on Patreon, we have hundreds of more tests coming.  We have only begun...

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