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Old March 22, 2013, 01:56 AM   #1
indy1919
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Why was YUGO ammo inaccurate in a Gewehr 88??

A Question. Went to a range with a guy testing his Gewehr 88 with Yugo 8mm ammo, Dating from 50 to 53..

Out of 10 shots 3 of the rounds failed to fire. The Primers showed good deep hits. The gun was on a bench and was being firing at a 12" plate at 50 yards. Of the 7 rounds that fired they were all over the place some even missed the 12" plate hitting high above the target.

So I tried to buy the Gewehr 88 from him for $10 telling him the barrel was burned out.. But he would not go for that deal...

So thinking that maybe this was a bad batch of Yugo 8mm, fired 5 shots of the same yugo out of a m24/47.. The hits could not have have been tighter. Even fired the failure to fire shells out of the m24/47 with good tight groupings.

So we put Romanian 8mm in the Gewehr 88 and it fired perfectly with real nice groupings..

So My Question is why did the Gewehr 88 not operate well with the Yugo ammo.. yet fire fine with the Romanian Ammo????
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Old March 22, 2013, 06:33 AM   #2
madcratebuilder
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50's Yugo 8mm has very hard primers. The bolt needs to be clean and you need a good firing pin spring. Some go with a increase power spring from Wolf. Inaccurate from worn barrel.
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Old March 22, 2013, 08:00 AM   #3
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Personally I would NEVER fire 50's Yugo in a Gew88. I've had many split cases with it in my 98 Mausers and I would hate to see what it would do in the 88 action considering it lacks the gas handling improvements of later designs.
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Old March 22, 2013, 08:51 AM   #4
Tidewater_Kid
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That GEW88 is not built to handle Yugo 8mm. Do NOT shoot full military loads in a GEW88. You need to verify the bore diameter before you shoot the GEW88 at all. I have two of these rifles and you have to be careful with them.

The Romanian ammo uses a very light 8mm bullet. The exact weight escapes me at the moment, but much much lighter than the 198 grain in the Yugo surplus. I have been told you can shoot the Romanian in these, but I would not make a habit of it.

These rifles were not designed for standard 8mm ammo. The bore can be as small as .311 (maybe smaller with Czech barrels). If you go shooting .323 bullets down tight barrels you are going to have problems.

If the rifle has been rebuilt by the Turkish armory, it "might" have a larger bore, but I still would not shoot WW2 surplus in it. Your life, your call.

TK

Last edited by Tidewater_Kid; March 22, 2013 at 09:00 AM.
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Old March 22, 2013, 09:51 AM   #5
Slamfire
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You were firing old surplus ammunition, ammunition that was discarded as unsafe by the Yugoslavians and sold to ignorant Americans, and you were firing it in a 1890’s vintage rifle.

You are lucky the ammunition was not so overpressure to blow up that old plain carbon steel receiver.

Also, that mainspring on that 1888, it probably dates to 1888. A 125 old mainspring needs to be replaced.
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Old March 22, 2013, 12:19 PM   #6
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older 8mm mauser ammo was .318 and barrels matched... later a .323 was adopted and many mausers have a marking on the barrel to differentiate bore diameters so soldiers wouldn't use the wrong ammo in them.

my guess is that his g88 was a 318 bore and that yours is a 323 bore. the ammo you tried in his might have been slightly underbore and better suited to his barrel.
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Old March 22, 2013, 12:41 PM   #7
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Pressure limits on the 1888 Commission Rifle is 36K CUP. Using modern or milsurp 8x57 in them is ...... foolish, at best ......... and hard on the gun (do you notice the headspace becoming excessive rather quickly?) ...... and eventually hard on the shooter, too.

Handloading, possibly with cast boolits, is pretty much the only safe/sane option for feeding these.
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Old March 22, 2013, 03:31 PM   #8
James K
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If it is dangerous to fire the new ammo in the 88 rifles, the Germans didn't know it since they issued them to reserve units along with the "S" size ammo.

Here is the real story. The Model 1888 had a .311"* BORE diameter, and a .318" groove diameter. That meant the grooves were only .0035" deep, and lands started eroding quickly with the powder of the time. So the decision was made, c. 1905, to change the groove depth and adopt a larger diameter bullet, called the "S" bullet, of .323" diameter. Model 1898 rifles were recalled and re-barrelled, but there were millions of the old Model 1888 rifles in the war reserve. What to do?

Well, what they didn't do was to re-rifle those barrels. They found the new ammo gave high pressure not because of the bigger bullet in the barrel, but because of the lack of room at the old chamber neck for expansion of the case neck. If the case neck didn't have room to expand and release the bullet, pressure went to the danger point.

So all they did was to run a new dimension reamer into the chamber to expand the chamber neck, and fire the new ammo. They altered many millions of those rifles to accept the new clips (chargers) used with the Model 1898, marked an "S" on the receiver ring, and issued them to reserve units. There was no ammo confusion. New ammo was in chargers, old ammo was in en-bloc clips. If the clip fit the gun, the ammo was OK.

Later, during and after WWI, many of those altered Model 1888 rifles were given or sold to the Turks, and some collectors believe the Turks made the alterations. They didn't - the Germans did.

Jim


*Dimensions in inches for convenience; the Germans used the metric equivalents.
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Old March 24, 2013, 01:02 AM   #9
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Quote:
If it is dangerous to fire the new ammo in the 88 rifles, the Germans didn't know it since they issued them to reserve units along with the "S" size ammo.
Oh, I'm sure they knew it ..... they just did not think ther reservists would fire it enough to matter ...... or they did not care. The Turks certainly did not.

I can tell you that 50K CUP loads in an 88/05 WILL do bad things to the recieviever, and fairly quickly.

I can also tell you that a short barrelled 88 carbine will not develop enough pressure to obturate with the max loads listed for the 88 in most manuals.
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Old March 24, 2013, 05:01 PM   #10
James K
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Hi, jimbob,

I have not been able to find the original pressure standard for the 8x57J (1888) military cartridge. Nor did I find any reference indicating that converted M1888 rifles failed in service.

Since you have access to better info than I do, I would appreciate references or links. Thanks.

Jim
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Old March 24, 2013, 08:35 PM   #11
Josh Smith
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I'm going from memory here.

The 88 receiver is rated at around 45kpsi. Original 7.92x57j was around 40kpsi average pressure.

Also, if I recall correctly, the SAAMI spec for any 8mm Mauser is 38.5kpsi. It's based on these older actions.

The Romanian surplus is safe as it stays true to the 1905 spitzer round -- the 7.92x57js. This is what the 88/05 will fire safely as the bullet has a small driving band.

The 198grn 7.92x57jsS is not safe to run through this rifle. Over-proof pressures and large bullet bearing surfaces may cause failures.

I recipe for the 7.92x57js I fire in my 1892 Amberg is 150 grain Hornady 0.323" bullets over 45 grains of Varget. This is a nice, soft shooting load. Check your manuals; like I said, this is going from memory!!! My notes are at the shop!!!

The mainspring from a Gewehr 98 will fit this bolt nicely, and I use the extra-power spring from C&R Surplus.

I once had a source for 0.318" bullets; if you have an non-converted 88, I'll see if I can dig it up again.

Regards,

Josh
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Old March 24, 2013, 08:51 PM   #12
jimbob86
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James K-

Upon looking at Speer #13, I see I was wrong .... they state on page 339, left column, 3/4 down the page, that "because of industry concerns over shooters using JS-type ammunition in the weaker (and tighter bored) model 1888 action, the industry pressure limit is unusually low - 37,000 CUP."

I was off by a whole 1000 CUP ......

They go on to state that their 8x57 max loads are around 50K CUP, and not to be used in any 1888 action.

As for bad things happening to an '88 from 50K CUP loads ..... that's from personal experience ...... 50gr of 414 under a 170r jacketed bullet is not a good thing to do to a late 19th century firearm ...... an ounce of "not a good idea" prevention is worth $250 worth of Gunsmith cure ....
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Old March 25, 2013, 09:28 AM   #13
Slamfire
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Books are excellent things to read often have interesting data. This is a book I recommend: Rifle & Carbine 98: M98 Firearms of the German Army from 1898 to 1918 Dieter Storz

Inside Dieter’s book are the material specifications for the M98 Mauser.

The material looks to be a manganese steel alloy, with copper added for easy machining.

I assume the material is in the normalized state, but the property requirements were Ultimate 78.2 Ksi, Yield 36.9 KSI, elongation 15%.

Carbon LT 0.40%
Manganese LT 0.90%
Copper LT 0.18%
Silicon LT 0.30%
Phosphorous LT 0.04%
Sulphur LT 0.06%

What he mentions in terms of manufacturing shows primitive process controls and that parts broke: Amberg Arsenal, retort ovens used till 1905, temperature judged by eye. Amberg M98 bolt lugs broke at the rate of 1:1000 rifles. The third lug was needed or bolt blowout would have caused injuries.

The 1888 series or rifles was about two generations earlier than the M98 and the metal in them would be even more suspect.

Those who are ignorant of the rapid progress in metallurgy, process controls, just assume, out of ignorance, that the steel in early rifles is as good as today. This is not so, but given that the natural state of humanity is ignorance, what can you do?
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