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A look inside special: comparison of 8x56r (Very Large)

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Zeliard
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A look inside special: comparison of 8x56r (Very Large)

#1 Post by Zeliard » Sun Jun 11, 2017 7:51 pm

Originally posted by carteach0.

A look inside comparison: 8x56r Austrian vs 8x56r Bulgarian.

In this expanded episode of ‘A look inside’ we’ll inspect and compare
two versions of 8x56r. A 1938 Austrian M30 and a Bulgarian version
of the same. Both samples were generously provided by the Hebrew Hammer.

The Austrian M30, made under German occupation in 1938 according to
the information I read, looks like this:

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And its cousin, a 1940 head stamped Bulgarian 8x56r with what appears to be a nickel
plated bullet, although I am unsure exactly what it is:

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As usual, all weights were taken with the trusty old RCBS 10-10 beam scale.
Dimensional measurements were taken wit Mitutoyo digital micrometers and
a Central vernior caliper. Bullets were pulled using an RCBS collet type puller
mounted in a an RCBS Ammomaster press. Coffee was fresh ground A+P brand
contained in an aluminum mug.

Never having working with this cartridge before, a little research was in order.
This meant delving into the Carteach0 library (third crate from the left,
two layers deep). The best tome found for nominal dimensions and
cartridge data happened to be a conversion manual, showing both the
cartridge and how to build it from other obscure cases.

I will highly recommend this book, ‘The handbook of cartridge conversions’,
to any advanced hand loader. It serves the wonderful purpose of
making it crystal clear exactly what is involved in making one
cartridge case out of another cartridge case. In fact, it’s so clearly
spelled out that no sensible shooter would wish to try it.
That, my friends, is one time saving book!

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We’ll begin with the Bulgarian.......

Exterior case dimensions were made first, and variations were found. Most impressive
were the over all length differences, a surprisingly large 0.019” starting at 2.995” and
ending at 3.012”. That is a substantial length spread. The bases ranged from .4900”
to .4924” with a 2.4 thousandth spread. The necks were quite difficult to measure as the
neck is tapered like the case body. I found an average neck taper of .004” from one end
to another. I suspect this helped with extraction on the straight pull rifles. Neck dimensions
varied from .3573” to .3600”. I tried to be as careful as possible to measure each case neck
at the same place. Case length variation was almost reasonable at .006”, from 2.183” to 2.189”.

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The Bulgarian sample had the primers sealed, but not the bullets. The bullets pulled
quite easily, even with the cases heavily crimped into the bullet cannelure. This proved
to be a blessing, as the bullet diameter is quite large for an 8mm round. The collet used
in the puller was ‘diameter challenged’, being a 30 caliber unit. The 8x56r
bullets measured at .330, quite a stretch!

The unusual bullet diameter makes reloading this round difficult. Jacketed
bullets are near impossible to find, leaving the handloader with the
option of casting his own lead bullets. This can be a fascinating
part of the handloaders hobby, often resurrecting a rifle from
non-shooting status to useful life.

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The powder is a cut flake of uniform proportions. It appears similar to that found
in the Yugoslavian 8x57, but clearly has a different texture. The powder seemed
fairly fresh despite its age.... being older than most of the people reading this.

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The powder charges weighed in at 50.8 grains at the lowest to 51.5 grains in the
highest. Not a bad spread given both the powder type and the manufacturing
conditions of the time (wartime).

The bullets pulled were fascinating. They are a boat tailed design with
an exposed lead indented base. The jacket has a distinctive silvery color
and appears to be nickel plated. The bullet does attract a magnet.
It has a deep tapered cannelure as well.


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In weighing the bullets, they had a fairly wide spread from 206.8 grains
to 208.0 grains. Their diameters measured from .3286” to .3300”, a very wide
variation of .0014”. More troubling than that, the individual bullets
had a diameter out of round variation of .001” each! Over a thousandth
of an inch from being round. That’s an accuracy killer if there ever was one.

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Being of a curious bent, I just had to know the nature of the jacket and
what appeared to be a steel core. I was incorrect in that thought.

I proceeded to cut one of the bullets in two with a cut off wheel, then
polishing the cut surface with 600 grit cloth. There is no steel core,
instead having an easily scratched soft lead core. The jacket
appeared to be a solid metal, instead of a plated bullet.

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The cases were berdan primed and weighed in with a low of 124.2 grains
to a high of 126.0 grains. Not a huge spread, but noticeable.

Initial conclusions on the Bulgarian: This ammunition does not appear to
be the most consistently made sample I’ve seen. Ok, I was being nice.
The bullet variations were real wowsers and the overall length spread
was pretty wide too. I don’t know what reputation the little 8x56r carbines
have for accuracy, but I suspect it could be better with ammunition of higher
quality than this.

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Now we’ll move on to the Austrian M30 8x56r round, dated 1938 on the headstamp.

This ammunition arrived in its enbloc clips, each bearing a Waffen stamp
matching that of the head stamp.

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The cases appeared clean and as new, clearly doing well for their age.

In dimensional measuring, I found the Austrian to be held to a higher standard
than the Bulgarian. OAL variations were a scant .001” at 3.005”
Case bases measured at .4905” with a very tight .0009” variation. Less than
one thousandth of an inch. Not bad! Neck diameters were tapered exactly as
the Bulgarian, but less so, at .0015”. The neck diameter ranged from .3561”
to .3591”, a spread of .0030” (Aint I good at this math stuff?!?). Case lengths
ranged from 2.187” to 2.194”, a .007” variation.

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The bullets were not sealed to the cases, nor were the primers. Bullet tension
was light and even, with a gentle pull being all that was needed. The cases were
lightly crimped into the bullet cannelure.

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The powder once again was a cut flake looking exactly like that used in the
Hungarian round. There was no noticeable difference between the two.

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Powder weights ranged from 47.4 grains to 48.0 grains. The variation of
.6 grains being a bit less than the Hungarian, although the charge weight
in general was several grains less in the Austrian than the Bulgarian.
The donor reports the Bulgarian ammunition is quite hot, and may have been
a machine gun loading.

Case weights with the Austrian ranged from 133.0 grains to 135.9 grains, a fairly
wide spread. The slightly higher case weight of the Austrian over the Bulgarian
caused me to wonder if the powder load difference was because of case capacity.

To check this suspicion I had to either fill the cases with measured fluid or
cut the cases apart. Never being one to shirk from power tools and
destruction, the choice was obvious. I cut the cases.

What I found was the Austrian 8x56r case had a significantly thicker
base than the Bulgarian case. This difference in case capacity could
easily account for the powder variation.

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In mentioning the task of cutting the cases, another incident must be related.
Naturally the live primers had to be either discharged or removed. Since I have
no firearm that would fire the primer, and no way to safely remove a live
berdan primer, ingenuity took over. My stroke of genius was to use a
propane torch to fire the primers. Brilliant, just plain brillaint................

Now, I did wear safety glasses, hold the case gently with pliers, and aim the
case mouth and primer in safe directions. I am not a TOTAL idiot, no matter
what my wife says, or my friends, or my kids.

The Austrian primers fired with one heckofa bang, blowing the flaming
primer across the room and emitting a large blast out the case mouth.

Cool..... I had to try that again. Yup..... KER BLAMMM.

He He.... now to try the Bulgarian. I have eaten Bulgarian food spicy enough
to strip paint. I expected their primers to spit fire too.

Nope.... the Bulgarian primers ignited with a wimpy anemic ‘foof’ and
pumped out a baby puff of smoke. The primer didn’t budge. The second case
did exactly the same thing.

Moral of the story? We.... I probably am an idiot. Aside from that, I would have
expected the Bulgarian to be weak or duds. The ammunition donor reports
the opposite, and that it’s sure fire and quite hot.

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Back to the semi-science..........

I noticed a visible difference in the case rim from the Bulgarian to the Austrian.
The Austrian version seemed thicker and more uniform. Applying the micrometer
showed the rims to be different by .008”, .044” vs. .052”. This should make
a difference with head space.

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The bullets pulled from the Austrian 8x56r were boat tailed and copper jacketed,
although they too attracted a magnet. Bullet weights varied from 206.5 grains to
207.6 grains. Bullet diameter was .3300”, give or take .0004”. Total diameter
variation was slightly less than .0009”, with 0.0” variation in roundness.

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Some conclusions.....

1) I might be an idiot, but that will not stop me.
2) The Austrian appears of better quality than the Bulgarian.
3) While the nickel bullets look neat, I bet they don’t shoot that well.
4) Quality military ammunition has a remarkable life span, with this ammo being clean and sure fire.
The Austrian in particular looked like new internally and externally. The cases were actually
brilliantly shiny inside.
5) This was fun.


Finally, a few graphs for those who enjoy the pretty colors.....

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Proud alumni of Transylvanian Polygnostic University. "Know enough to be afraid."

"Vertroue in God en die Mauser".-Faith in God and the Mauser.

"Send lawyers, guns and money." -Warren Zevon

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