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PostPosted: Thu Jan 22, 2015 11:09 am 
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Lance Cpl
Lance Cpl

Joined: Mon Jan 19, 2015 6:58 pm
Posts: 15
To me the transition period from BP to smokeless is interesting. According to legend a French soldier skipped out and joined the Germans prior to WWI. He took with him the 8mm Model 1886 Lebel with the new ammunition loaded with Poudre 'B', a new smokless powder. At first the German army paid little attention until the Kaiser learned of the new weapon. A commission reviewed the rifle and ammunition and adapted it for the German Army. The new powder developed pressures higher than BP and finding the right blend of steel to contain the pressures as well as duplicating the powder began. The cartridge was designated the Patrone 88 having a round nose bullet of 225 grains. It was later changed to a spitzer design and designated as the S Patrone in 1905 using a double base powder and a bullet of 153 grains. More power and flatter trajectory was gained. The round is a 7.92X57 and basically called the 8mm Mauser. Without going into detail about how and what was changed on the GEW88 during those years up to 1915 when it was no longer issued - there are some interesting facts to note and cause confusion to those who may have one or see one for sale. The rifle came in two variations to begin with. The GEW88 rifle and the KAR88 carbine. The were originally loaded by means of the EnBloc whiich when empty the clip would drop from the bottom of the receiver. Later it was modified for a stripper clip and the bottom of the receiver covered with a plate. The M-1 Garand uses the EnBloc design but ejects upwards. The bore of the rifle is said to be .318 and this is where the real confusion starts. Actually that is the depth of the grooves. There is no difinitive way to determine what bore the rifle is without slugging it for measurements. The GEW98 has a groove Dia of .323 and the modern 8mm ammo of U.S. make will measure .323 but it is loaded down in case it finds it's way into the chamber of the .318 land Dia. Modern 8mm is about equal to the 30-30. During the change from round nose to spire point some of the GEW88's were rifled deeper to accept the .323 bullet and the throat extended and they will be stamped with a 'S' on top of the receiver. Sounds straight forward - but it's not. Never trust what was - slug the bore to be sure. Also some will have the letters 'NM' on the left side of the receiver. It stands for 'New Material' and for all intents and purposes it was redesigned to handle the hotter .323 spire point ammo. Don't trust this either. The receiver is stronger but still uses the two piece bolt plus the fact that these arms were sold surplus to other countries such as Turkey where they performed their own modifications. So once again - slug the barrel. It would also be wise to cast the chamber for diminsions. The barrel is covered with a sheet metal shroud and the idea was to protect the barrel from weather and being hit. Often times the barrel will be corroded from moisture and deeply pitted. The barrels are pencil thin so caution should be used if they are to be fired. After using machinist pin gauges on the bores of these rifles I have found the bores to be from .311 to .314 for both the 88's and 98's. The groove depths have been .316 to .320 for the 88's and .321 to .324 for the 98's. The reason for this is wear to the cutting tools over time before they are replaced during manufacture. This doesn't include the probability of wear from use. I have pin gauged a few 98's from WWII and found them to be completely shot out where the pin gauge would drop in the bore until it hit a tight spot. Since Germany lost both wars the rifles were not recalled to the armory to replace worn parts. Some can be found that were recalled during the conflicts and are in really good shape. Some have been repaired by other countries that purchased the arms surplus. Most of the '03 Springfields were recalled and repaired before sales were made to the civilian market which accounts for their fine accuracy.
I have both a 88 rifle and carbine and both have grouped 1 inch at 100 yards from a machine rest. I use only cast bullets with loads running close to 1700 fps. The carbine likes a bullet of .324 diameter and the rifle likes .320. Both are loaded with Trail Boss and Red Dot powders. If you happen to purchase one of these commission rifles I would suggest to do your homework on it before shooting. Have it checked by a gunsmith and build your loads to the rifle and not the caliber. You will be rewarded with an accurate shooter.


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PostPosted: Sun Mar 15, 2015 11:36 pm 
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Corporal
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Joined: Mon Jul 26, 2010 12:07 am
Posts: 57
Location: central washington state
I had a m-88 and sold it to fund another project. if the receiver is marked with an s it is supposed to be safe with modern ammo.. I shot mine mostly with cast but did learn a few things I would like to share. some of this is my observation and may or may not be completely factual. on the rifle I owned the throat was very long I think to lower pressure. most lots of old 8mm ammo had actually had bullets of around .321.. by that I mean the ammo for model 98 was undersized and this helped make it safe to shoot in the m-88. long forcing cone, undersized bullets and not loading the 8mm ammo as hot as it can be. I to would limit these rifles to cast bullets and low pressures, but I don't think there is going to be a blown up rifle with a few standard 323 bullets. one of my favorite things to do is learning about all the rifles I buy. I read everything I can find, shoot reload and shoot some more. I kick myself for selling my m-88 and my 1907 lebel. argie1891


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PostPosted: Mon Mar 16, 2015 7:29 am 
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Lance Cpl
Lance Cpl

Joined: Mon Jan 19, 2015 6:58 pm
Posts: 15
They are an interesting rifle. I shoot mine with cast bullets sized to .321. At the time they were built the Jager sporting rifles with split receivers such as the Styer and others all had the .318 bore. The drillings I have shoot the 7.92 normally called 8mm rimmed round and those bores are .318 as well. No doubt the GEW88 was pressed into service and launched a larger diameter bullet at higher velocities and the longer throat allowed for the bullet to swage down to the smaller bore without spiking pressure. It worked 100 years ago. Since the arms are obsolete I personally see no need in shooting a full service charge. I know that American ammo is designed to be fired without harm in these old rifles and the 8mm has been loaded down to reduced pressure. Of course that is considering the rifle is in good condition. I keep my loads in the 12 to 14 hundred FPS range with a soft alloy bullet. Accuracy is very good and I can hit clay pidgeon targets at 100 yards with very few misses - from the bench. Recoil and report is very mild and makes for a pleasurable time at the range. Another reason for cast bullets is to reduce wear on the rifling and I brew up my own lubes so when I encounter a rifle with a dark bore I add canuba wax to the brew and it helps to brighten up the bore over time.


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