I have a Gew88 that I've been shooting for several months with Yugoslavian surplus 8mm. The other day, a guy told me that this is very bad for the rifle and could eventually cause it to blow up. I don't believe him because I've put over 200 rounds of it through the rifle with no problems. No split cases. Nothing. Is there anything out there that backs up his claim?
Gew 88 - Bore Sizes and Ammunition
Archetype
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No, they MOST obviously are not.
And now read my posting again. And again. And then again. Pretty please, for the sake of correctness. You are introducing inaccuracies where they do not belong.
Carcano
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623 Posts
How are they incorrect & based on what? I'm not introducing any inaccuracies, just presenting facts. If you think they're wrong, I'd like to know the correct numbers.
The correct barrel specifications for the respective old and new cartridges are:
Military Patrone M/88: 7,90 mm / 8,10 mm
Military S-Patrone: 7,89 mm / 8,20 mm
Note that these are minimum specifications, with an allowed tolerance upwards.
Civilian "I" caliber, normalized in 1938 (can widely differ, may often be tighter): 7,80 mm / 8,07 mm
* * *
Nominal civilian bullet (maximum) specifications are:
Civilian S: 8,22 mm
Civilian I: 8,08-8,09 mm
Real measurements are often different, varying from producer to producer. Also note that on an assembled cartridge, the widest bullet diameter may frequently be hidden inside the case neck.
I will try to add nominal military S-Geschoss and sS-Geschoss specifications later.
* * *
Am adding my sources, as Nick has reminded us all:
RWS (Ed.), Werner Lampel (auct.): Schießtechnisches Handbuch für Jäger und Schützen, 2nd ed. 1940, p. 42-44
Dynamit Nobel (Ed.): Wiederladen. Ein praktisches Handbuch für Jäger und Schützen,
9th ed. 2002, p. 254 (8x57 I), p. 305-306 (8x57 IS)
DEVA (Ed.): Wiederladen - Vorbereitung und Praxis,
5th ed. 2005, p. 342 (8x57 I), p. 354 (8x57 IS)
Military Patrone M/88: 7,90 mm / 8,10 mm
Military S-Patrone: 7,89 mm / 8,20 mm
Note that these are minimum specifications, with an allowed tolerance upwards.
Civilian "I" caliber, normalized in 1938 (can widely differ, may often be tighter): 7,80 mm / 8,07 mm
* * *
Nominal civilian bullet (maximum) specifications are:
Civilian S: 8,22 mm
Civilian I: 8,08-8,09 mm
Real measurements are often different, varying from producer to producer. Also note that on an assembled cartridge, the widest bullet diameter may frequently be hidden inside the case neck.
I will try to add nominal military S-Geschoss and sS-Geschoss specifications later.
* * *
Am adding my sources, as Nick has reminded us all:
RWS (Ed.), Werner Lampel (auct.): Schießtechnisches Handbuch für Jäger und Schützen, 2nd ed. 1940, p. 42-44
Dynamit Nobel (Ed.): Wiederladen. Ein praktisches Handbuch für Jäger und Schützen,
9th ed. 2002, p. 254 (8x57 I), p. 305-306 (8x57 IS)
DEVA (Ed.): Wiederladen - Vorbereitung und Praxis,
5th ed. 2005, p. 342 (8x57 I), p. 354 (8x57 IS)
So the Czech Barrels, are dead on (german) civilian barrels (Czech Military barrels) so......... is there a commercial round currently available that meets the spec. Also.... Carcano... What is the European distinction between the 8mm Mauser round and the 8x57JS (such as PPU rounds). Is this a Civilian vs Military designation? If so, is it safe to assume that 8mm Mauser round is intended for the civilian diameter barrels?
I have used US inch in my posts because they are about shooting the Gew-88's safely, the shooters here will be measuring their rifles with inch spec , US bullets are sold in inch specs, and most of the readers here can relate better to inch. The original ammo used a bullet type different from US made bullets, so US made bullets have to be loaded differently. A measurement is a measurement no matter if it is in inch or metric, they can be converted very accurately either way. Since there were clearly 3 different land / groove combinations used by the Germans [ plus other sizes from other countries ], plus the 7.90 [ .3110 ]
, 8.10 [ .3188 ] is not one of them. Since the post is about SHOOTING the rifles and none of the EXISTING rifles will be found with that bore, it is not relevant. What is relevant is the shooter measuring the bore in the rifle he he is wanting to shoot and using a bullet size that fits HIS rifle, not what fits a book. The fact that all the existing German barrels fit into one of those 3 sizes, by the year it was made means a shooter will find his rifle to have one of them. mag
, 8.10 [ .3188 ] is not one of them. Since the post is about SHOOTING the rifles and none of the EXISTING rifles will be found with that bore, it is not relevant. What is relevant is the shooter measuring the bore in the rifle he he is wanting to shoot and using a bullet size that fits HIS rifle, not what fits a book. The fact that all the existing German barrels fit into one of those 3 sizes, by the year it was made means a shooter will find his rifle to have one of them. mag
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13,698 Posts
I am sorry - no, it is not about shooting. While the whole thread started with the post about shooting, I made it sticky for a completely different reason. Let me restate it - it is about the bore sizes of Gew 88 and its modifications and the ammunition used in them.
Feel free to shoot whatever you want - lead cast, original, new - it is your personal business. Slug as much as you want, use metric or standard calipers - your business again and we are not discussing it here. The topic of the thread is about something else and I would like the posts to be centered on or close to it. Please.
I do not know any other way to determine sizes other than measuring with a tool made for measuring. My posts clearly state the 3 main German bore sizes, the dates they where used, and why. I also state ammo sizes [ taken from a wide selection of original ammo ], bullet dia, case measurements, and how they fit the rifles. I cover what , when, and if anything was modified,, and why . The above is everything you have posted in RED . All of that is related to shooting, as that is what the rifles were made to do, and is why most of the people here ask about it . There is alot of misinformation out on Gew-88 rifles, and it is causing many problems. I do think it is relevant to keep people from hurting themselves or their rifles by reading incorrect information. A perfect example is the latest Gew-88 I got bought. Through ignorance caused by misinformation he read, the former owner ruined the chamber on a Czech barreled rifle by trying to "polish" it out since it would not chamber "Ss" ammo. He was told since the rifle had the "S" it was for .323 ammo. Of course "Ss" ammo will not fit the chamber of a fresh Czech barrel, and would be dangerous if he did get it in and fired. I am sorry if I thought one of the functions of this board is to help and protect people from getting hurt. mag
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13,698 Posts
That's why I made the point that only reliable sources should be quoted. In any case, all sources of information should be listed so anybody can choose what to believe or not. Barrel slugging may be useful, but the only information it provides is on the manufacturing tolerances.
Again, please, quote original and reliable sources, not just personal opinions based on single events or a limited sample.
Again, please, quote original and reliable sources, not just personal opinions based on single events or a limited sample.
The problem is that many "sources" are incorrect. Over 100 Gew-88 rifles are not a " limited sample" . Real rifles are just that, real rifles. With such a large sample checked, tolerances are not a problem. With my shooting, cleaning, and measuring of over 1000 different military rifles, "wear" is not a factor. I can see it, and take note of it. When 20 pre mid 1890 rifles ALL have the same bore size +/- 0.001 and when all mid 60 1890 to 1896 rifles ALL have the same bore sizes as each other, but different from the pre-1890 rifles. All 24 1896 and up, plus post 1896 rebarrels have a stamp and all have the same size bores, but different from the other two. That is a GOOD source. Since the rifles all do exist, it does prove the bores sizes. The same goes for the ammo, I have P-88 ammo dating from 1892 to 1902, and "S" ammo dating 1904 to 1918 . mag
The literature has suggested (implicitly) that the bore size was never decreed to be changed. However, Mag has validly challegend it, when according to his measurements, he posits that the groove size initially stayed the same, but the lands (= bore size) was altered:
"With ORIGINAL barrels the bores sizes where: 1889 to mid 1890- .314 - .3215 ,,, Mid 1890 to mid 1896 .311 - .3215 ,, Mid 1896 to end - .311 - .323+ ."
These measurements are concilable with the German wording, which states that the Z stamp denotes an altered Zugtiefe (groove depth). Normally, everybody would assume that a) the grooves henceforth would be cut deeper, but indeed it would also be possible b) to bore the barrel blank less wide and keep the groove cutting teeth of the tooling equal.
a) The former seems normal and expectable, because the barrel-cutter has to be exchanged every so often anyhow, and because the cutting teeth are re-adjusted during the manufacturing process. The drills would last longer, and their lack of width due to use can be partially compensated by the subsequent lapping process.
b) The latter would necessitate totally new tooling of the barrel drills.
Carcano
"With ORIGINAL barrels the bores sizes where: 1889 to mid 1890- .314 - .3215 ,,, Mid 1890 to mid 1896 .311 - .3215 ,, Mid 1896 to end - .311 - .323+ ."
These measurements are concilable with the German wording, which states that the Z stamp denotes an altered Zugtiefe (groove depth). Normally, everybody would assume that a) the grooves henceforth would be cut deeper, but indeed it would also be possible b) to bore the barrel blank less wide and keep the groove cutting teeth of the tooling equal.
a) The former seems normal and expectable, because the barrel-cutter has to be exchanged every so often anyhow, and because the cutting teeth are re-adjusted during the manufacturing process. The drills would last longer, and their lack of width due to use can be partially compensated by the subsequent lapping process.
b) The latter would necessitate totally new tooling of the barrel drills.
Carcano
You got my point. When you just read about it, it SEEMS to say " grooves CUT deeper ". But the groove can be MADE deeper by a smaller bore, and it is clear when you look at a lot of rifles and the bores are smaller that that is what they DID. The next point is not to confuse that change with the "Z" marked barrels. The "Z" barrels took the 2nd type and DID cut the grooves deeper. All rifles made after 1896+ have a "Z" stamped on the receiver and have a .311 - .323+ barrel. Earlier rifles that have been rebarreled have a clearly "added" on "Z" stamp and have the .311 -.323+ barrels. The barrels are also stamped "Z" . I have yet to see a rifle that did not match this pattern, and this pattern DOES match the German manuals if you look at it in this light. mag
If this was a case in a court of law where the issue was to determine the bore size of GEW88 rifles, the best evidence would be the rifles themselves, which would then be examined by experts to determine their bore size. Quotations from old books would not be the best evidence, since the rifles still exist, and, in fact, would not even be admissible evidence to determine bore size as they would be "hearsay" and thus inadmissible. This is exactly what MAG has done. I also have done exact measurements on my collection of more than 30 GEW88 rifles and I won't bore you with each rifle's measurements, but what I have found generally supports MAG's conclusion. My GEW88s with matching barrels dated prior to 1896 show .311 x .321-2 bores; my later GEW88s and the ones with Turk replacement barrels show .311 x .323-5 bores; and my GEW88s with Czech marked replacement barrels show .308 x .317-8 bores.
69khz mentions “189x-??? .318" / .311 A small minority of Gew 88 fall into this category” If my memory is correct this statement is based on a rifle with an imperial barrel that did not match MAG’s statements. I several years ago conversed with MAG about my Kar 88 which has an imperial barrel (Krupp made) that slugged out at 0.319 - 0.3195. I redid this three times for MAG as well as checking my Gew 88/S and 88/05 (0.321 and 0.323 respectively). While MAGs results are very valuable and any theory on the bore sizes of the 88s be compatable with his results, it is not necessarily the full story. Also (tongue in cheek) in court would not a chain of custody be established for each rifle with proof it had not been reworked or rebarreled? I don’t think matching serial numbers would be considered proof as they are easily added to a replacement barrel.
All the Turk rebarrels that I have seen have modified M-93 8mm barrels on them and measure the same as Turk 8mm 1893 Mausers, .311 - .323+ . I remember the above carbine having Civilian proofs on it, which would mean a civilian spec barrel. I have seen many K-88's in full military condition with the civilian barrel. mag
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