The Accurate Reloading Forums
8mm bore size?
08 June 2006, 19:26
blackbearhunter8mm bore size?
I fired my new to me 8mm mauser with PMC 170gr.SP factory ammo.I can take a new round/bullet and it fits in the fired case with ease.Does this mean my bore is .323 with out a doubt?Can a .318 bore size allow this to happen also?Just wondering.

I have had 2 gunsmiths look at the old 1917 gew sporter and both said it was .323 but neither slugged it.One said the rifle had been rebuilt for service in ww2 and could be a old ss rifle,then sported.It is a Amberg action.Should i be able to reload it close to 30-06 & 308win. power?I read the PMC loads are sorta mild...30-30 speeds
Also does anyone have any idea what bullet brand the PMC 8mm 170gr,soft point is?What do you guys recommend for bullets/loads in these old girls and will 180-170gr,be the best all round bullet weight?I have a lot of testing to do and i really like the little rifle and iam looking forward to shooting it alot...it seems to have no recoil and is big time fun to shoot.I just want to have it loaded for blackbear just in case i walk right on top of one in the foggy/misty mountain laurel thickets iam prone to haunt from time to time in the fall...Something keeps telling me 200gr.nosler would be the ticket?Any suggestions?I no diddly about mausers but want to learn.Thanks in advance!

08 June 2006, 19:57
StonecreekIt is easily possible that a .318 barrel might have a chamber/throat that would accept .323 ammunition.
Surprisingly, a .323 bullet fired through a .318 bore swages down rather easily and doesn't raise pressures by all that much. Your rifle is likely a .323" bore, but even if it isn't, if you are getting acceptable accuracy from your rifle I wouldn't hesitate to reload for it using published data. If you have a chronograph and are experienced at working up loads, there's no reason you can't approach .30-06 velocities with 150-175 grain bullets. However, if you don't need such velocities, it is probably wisest to stop at .308 levels and enjoy your classic rifle without apprehension.
The 200 grain Nosler Partition should work just fine for black bear (or anything else). However, it is unnecessary for such game. At the relatively moderate velocities you will likely use your gun, anyone's standard cup-and-core bullet will do an excellent job on deer-to-black bear sized game.
quote:
Originally posted by blackbearhunter:
I fired my new to me 8mm mauser with PMC 170gr.SP factory ammo.I can take a new round/bullet and it fits in the fired case with ease.Does this mean my bore is .323 with out a doubt?
No, this simply means that the chamber is not cut with a tight neck - which would in any event have been VERY surprising for a Mauser.
- mike
*********************
The rifle is a noble weapon... It entices its bearer into primeval forests, into mountains and deserts untenanted by man. - Horace Kephart
08 June 2006, 22:08
vapodogquote:
Surprisingly, a .323 bullet fired through a .318 bore swages down rather easily and doesn't raise pressures by all that much.
Let me rephrase this please.....
"It's ok to fire bullets as much as .005" oversize in rifles using copper jacketed ammunition"
Stonecreek.....am I to understand this is what you meant in that statement?
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08 June 2006, 22:29
Poleaxquote:
Originally posted by vapodog:
quote:
Surprisingly, a .323 bullet fired through a .318 bore swages down rather easily and doesn't raise pressures by all that much.
Let me rephrase this please.....
"It's ok to fire bullets as much as .005" oversize in rifles using copper jacketed ammunition"
Stonecreek.....am I to understand this is what you meant in that statement?
Yes, the real issue is whether or not the chamber has sufficient room to allow the neck to freely release the oversized bullet. Provided it does and is not crimping the bullet then yes, the bullet will easily swage and not significantly raise pressures. If i'm not mistaken Hatcher and others proved this.
09 June 2006, 00:42
BFaucettquote:
Originally posted by blackbearhunter:
.... Should i be able to reload it close to 30-06 & 308win. power? ....
Just some data to show what the 8x57JS is really capable of:
http://www.rws-munition.de/http://www.sellier-bellot.cz/It hangs right in there with the .308 Winchester and the .30-06 Springfield.
For my Rem Model 700 Classic in 8x57JS, my handload is a 220 gr Woodleigh RN at 2400 fps (2402 chronographed average). As you can see, this load knocks the snot out of Warthogs.
Cheers!!
-Bob F.

09 June 2006, 05:38
bartschequote:
Originally posted by BFaucett:
Just some data to show what the 8x57JS is really capable of:
http://www.rws-munition.de/http://www.sellier-bellot.cz/
GREAT CHART

roger
Old age is a high price to pay for maturity!!! Some never pay and some pay and never reap the reward. Wisdom comes with age! Sometimes age comes alone..
I think factory US made 8X57 JS ammo is not loaded to European specs nor to maximum pressures because of the possible bore diameter problem. I inherited a sporterized 8X57 Mauser and assumed it was a .323 barrel, then decided to go for a rechambering to 8X62 and start pushing the envelope. The gunsmith (Duane Wiebe) then informed me that was a .318 bore and I was astounded considering the number of factory loaded rounds (Remington) that had been shot through it with no problem. I decided to have it rebarrelled with a 9,3 X 62.
_________________________________
AR, where the hopeless, hysterical hypochondriacs of history become the nattering nabobs of negativisim.
09 June 2006, 16:29
hawkinsWhen the Germans converted .318's to .323 al they did was re-throat the chamber. After the bullet moves 1/2 inch swaging is over. A tight neck on the other hand is a bomb.
Good Luck!
09 June 2006, 17:17
El Deguelloquote:
Originally posted by Stonecreek:
It is easily possible that a .318 barrel might have a chamber/throat that would accept .323 ammunition.
Surprisingly, a .323 bullet fired through a .318 bore swages down rather easily and doesn't raise pressures by all that much. Your rifle is likely a .323" bore, but even if it isn't, if you are getting acceptable accuracy from your rifle I wouldn't hesitate to reload for it using published data. If you have a chronograph and are experienced at working up loads, there's no reason you can't approach .30-06 velocities with 150-175 grain bullets. However, if you don't need such velocities, it is probably wisest to stop at .308 levels and enjoy your classic rifle without apprehension.
The 200 grain Nosler Partition should work just fine for black bear (or anything else). However, it is unnecessary for such game. At the relatively moderate velocities you will likely use your gun, anyone's standard cup-and-core bullet will do an excellent job on deer-to-black bear sized game.
Correct! IF your fired cases will freely admit a .323" bullet through the case mouth, you can use .323" bullets in it, regardless of whether it actually has a .318" groove diameter!
"Bitte, trinks du nicht das Wasser. Dahin haben die Kuhen gesheissen."
09 June 2006, 18:26
iwzbeemanWhy not take a lead slug, a fishing worm weight works well, drive it down the bore a ways, then tap it back out and mike it???? Then the guess work would not be needed.
09 June 2006, 19:21
BFaucettYeah, I agree... slug the barrel and find out. If it was mine, I'd want to know whether it was .318" or .323".
-Bob F.