Small and Large 9 x 19mm, Primer flash hole's

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Small and Large 9 x 19mm, Primer flash hole's

Post by Homer » 10 Dec 2018, 2:00 pm

G'Day Fella's,

Some time back, I purchased 5000 ish x once fired Federal Cartridge " FC ", Non Toxic " NT ", 9 x 19mm/9mm Luger/9mm Para cases.
When I was washing and checking these cases out, I noticed that there was a mixture of cases with both Standard size primer flash holes, and also cases with Larger than Standard primer flash holes, in all these cases.

Here they are, on the drying tray.
DSCN0732 (1).JPG
DSCN0732 (1).JPG (1.59 MiB) Viewed 190 times

FYI, traditionally, the priming mixture used in most modern primers, was/is a Lead Styphanate based compound.
This along with Lead (PB) bullets, had some serious and detriMENTAL health effects, on people that were exposed to all this airbourn Lead (PB).
Most of these Lead exposures, occured at indoor ranges, so lots of Police and security people, were exposed to it, whilst training there.
Some time after this was identified as a problem, the authorities specified only Lead Free ammo, could be used on their ranges.
So the manufactures had no choice but to produce ammo that complied with these specifications, or miss out on lucrative supply contracts...............,

From past experience with these things, I wanted to know if or what effect these slightly larger flash holes would have on both Internal and External ballistic performance.
Earlier this year, I loaded up 10 of each of the following 9 x 19mm loads, in cases with traditional/Small and Large primer flash holes.
125 grain X-Treme, total metal jacket bullet,
5.5 grains of ADI, AP100 powder,
Federal #100 primer,
FC, NT cases (Large flash hole)


125 grain X-Treme total metal jacket bullet,
5.5 grains of ADI, AP100 powder,
Federal #100 primer,
FC, NT cases (Standard size flash hole).

Here are some images of these cases, and their primer flash holes, L to R: FC, NT Large Primer flash hole and Crimped Primer, FC, NT Standard Primer flash hole and Uncrimped Primer (and for comparison purposes- Winchester Standard and Uncrimped cases).
DSCN1201.JPG (968.78 KiB) Viewed 200 times

Inside (the same Six cases, in the same order)
DSCN1196.JPG (554.66 KiB) Viewed 200 times

DSCN1202.JPG (999.55 KiB) Viewed 200 times

Their Pre and Post crimped in primer pockets.
Crimped Before (Right) and After crimp was swaged out (Left) - with an RCBS tool.
DSCN1208.JPG (673.51 KiB) Viewed 200 times

After being reminded about this testing by a mate of mine, late last week, I went to the range and conducted a basic test on these same loads.
These were fired thru my HS-2000, 9x19 pistol, which has a 127mm/5" barrel.
The first of the three Oehler 35P screens, was 10 ft from the pistols muzzle and the temperature was 27*Celcius.

The traditional/Standard primer flash hole loads, provided an average of velocity of 1029fps.
The Large primer flash hole load, provided an average of 1056 fps.
So the loads assembled in the FC, NT cases (with the Large primer flash hole), gave an average of 27 fps more velocity, than the FC, NT cases with the Standard size flash holes.
Also, there was no percievable difference or feel, in the firing of these different loads, in the polymer framed HS-2000 pistol.

Hope that helps

D'oh! and Merry Christmas
Posts: 391
Australian Capital Territory

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