8mm Mauser ???

[gnoahhh]

I'm betting that the OP did indeed measure bore diameter, what he needs to do is measure his groove diameter. A lot of people are still confused regarding those two terms.

[Moonie]

Also note, slugging a sewerpipe barrel will not necessarily give you accurate measurements. Gotta get that barrel spotless before slugging for accurate numbers.

[gew98]

gew98 post is accurate. The actual, nominal groove diameter is 8.15mm (.32087). I know of no 98's that where barreled for SA with the Czech .316 groove barrels.


Frank

Frank ; That's because there were no czech .318 mauser98's...only gew88's....reading comprehension is a must .

[dh2]

ok I am try for a pic here

[Doc1]

No offense to your photography skills, but I can hardly make that out. That *looks* like the Spanish Air Force eagle that was stamped on the Air Force-issued M43 Spanish M98 Mausers. If what I've just written is correct, you have an M43, which is a large ring M98 and will definitely have a nominal .323 groove diameter. Assuming the rifle is in good condition, it will be safe to use with any commercial or .mil 7.92x57 ammunition. Again, don't rely on me for identification: Check Goggle Images for M-43, M43 and Spanish Air Force Mauser and of course, if you are not qualified, have the rifle checked with your gunsmith for head space and condition.

Best regards
Doc

[crashguy]

I found 98 Mauser in very good condition. It has not been changed in any way , I have slugged the bore and come out with .318 inch.
I have started wanting to shoot cast boolits out of it I have the mold, new brass, reloading die's and gas checks but the .321 sizing die has been repeatedly backordered, I want to shoot this rifle to see what it will do.
I picked up a box of 8mm Serria game king 150 gr bullets lable shows them to be .323 inch , Serria manual has a warning about this.
What do I do about this is this bullet safe to shoot in this rifle or should I just wait on the sizer die?

How about the Lee .314 push through die and ream it to .320 or .321 http://www.midwayusa.com/product/480...ProductFinding

[dh2]

Spanish Air Force eagle that was stamped on the Air Force-issued M43 Spanish M98 Mausers
I am starting to get that answer a few times now. I have cleaned and slugged the barrel repeatedly and got .318 to .3185 every time , it does look to be in very good condition . I think it may be a barrel change from some ones rebuild

[LAGS]

If it is a Spanish Air Force, then you may be slugging the barrel correctly, but Not Measuring it correctly.
Are you measuring the Fatest part of the Slug, or the diameter down in the rifling grooves on the slug ?
The Grooves in the barrel are the part that is highest on your slug. That represents the Groove Diameter, that you are looking for.
The Low part on your Slugging Slug is the BORE diameter.
You are looking for your GROOVE Diameter.
Also, just to be safe, How are you slugging the barrel ?
If you have a rough bore, then it will strip off the rifling, or high part of the slugging slug and give you a false reading.

I just did some checking on some of my Mauser 8mm barrels .
The Bore diameter runs from .313 to .316. I checked it with the mandrals that fit my Barrel Crowning tool.
The Groove Diameter runs from .323 to .326
I think you are measuring the Bore Diameter, or the Groove Diameter is being Stripped off is you have a rough bore, or you are starting off with a slug less than say .328

[Moonie]

I have a Spanish M43. It slugs .324 and loves shooting the Lee karabiner above 35gr H4895 at 1,850fps.

[EDG]

The German ammo used before the 1905 conversion used a .318 bullet but the barrel was NOT .318 ever.
The barrels measure .3205 to about .321 for groove diameter.

The long long long throat for the heavy round nosed .318 bullets permitted the short stubby 154 grain spitzers to squeeze down to .321.

There is a long discussion about GEW 88 and Kar 88 barrels on gunboards. You can look in the Mannlicher forum for a sticky.

http://forums.gunboards.com/showthre...and-Ammunition

[dh2]

I am sluging the barrel by taking a pure lead ball force it through the barrel from muzzle to action with a 5/16 rod and hammer.
measure the top of the rifleing (the bigger measurement) giving me .3185.
other rifle I have done confirm to me my ,method is correct 444 Marlin .432, 45/70 .460, 7mmx57 mm Mauser .286
I am no expert on mausers , and working with the 8mm Mauser is all new to me , before they all was used for the action. I can not under stand why I come out with the .318 barrel. un less it has been changed at some point.

[nekshot]

sounds like a .318. I love mine! I use a rcbs 32 mold for cast and use hornady 32-165 ftx bullets swagged down a wee bit. Mine is a german sporter and is incredibly accurate. I wonder if your neck is for the early 318 8mm or the current 8mm. Mine is a .318 bore chambered with a 8mm .323 bore reamer. Once I figured it out it is no problem.

[LAGS]

You did not say what Diameter Ball you are startimg off with.
If the Ball is just about the same diameter as the groove diameter, thn the ball is still hitting on most of the radius and can start to Roll in the barrel ever so slightly shaping it undersized and give you a False reading.
I start off with a ball that when pounded into the muzzle, will cut a Ring of Lead off, and the slug comes out the other end of the barrel in more of a Cylinder shape.
But for a true reading, I would do a Muzzle Casting at least 1 1/2 " long with Cerosafe or even Epoxy if you Wax the inside of your barrel and use a patch over a 1/4" brass rod for a plug.
The rod and Patch stay 1.5" from the end of the muuzzle when you pour the epoxy plug.
Let it fully cure, and pound the rod out from the Breech end.
Do Not, Just Stuff a Plug of patches in the barrel about 1.5" into the muzzle and fill up the muzzle with epoxy or even Cerosafe.
The Wad will be like a Pillow, and you loose force to pound it back out of the barrel when the slug is hardened.
We call that "Over Ragging"