Sauer 8x60 Mauser stamping help

[xarcher]

Hello all. Am new to this forum, which came highly recommended by someone who was trying to help me figure out my 8x60 mauser sporting rifle. I inherited this gun over 10 years ago along with about 60 rounds of ammo. Shot it back then but it hasn't seen the light of day much since then. Got the urge to find out more about it recently. See first 2 pics
IMG_2637.jpgbarrel underside.jpg
Here is what I know (or at least think I know) based on what I have read/been told.
- I have read alot about the .318/.323 caliber options and the I and S suffixes. So I think I have a pretty good handle on the possibility that this could be either caliber and that I should positively verify which one it is before proceeding. Perhaps my decision to shoot this over 10 years ago was part blind faith that the bullets that came with it were the proper ones.
-The bullets that came with the gun are marked 8x60S (see pic)
IMG_0672.jpg
- I have not yet slugged the grooves, but I miked the muzzle and measured .324 across the grooves (see pic)
IMG_0660.jpg
- Here are the barrel stampings. I have had one guy tell me that 7.8mm signifies it passed a 7.8mm bore slug which translates to a .323 groove, but have had a second guy tell that 7.8mm signifies .318 groove. Can someone break the tie. Or if you are so inclined, please decipher the whole stamping for me.

Once I slug the grooves and cast the chamber, my ultimate goal is to mount a scope, work up some hand loads and drop the hammer on an animal or two. Then return it to safe storage. So to that end, if someone can help me find a smith that can make and fit me a set of claw mounts for a yet to be purchased scope.
IMG_2646.jpg

I have many more pics but the posting is limited to 5. See next post for more pics

[xarcher]

More pics.....
IMG_2639 - Copy.JPG IMG_2637 - Copy.jpg IMG_2650 - Copy.JPG Barrell - Copy.jpg Caliber mark on barrel - Copy.jpg

[xarcher]

More pics
Barrel Serial Number.jpg Bolt Stamping.jpg Serial number on barrel underside.jpg Stamping on right side of barrel.jpg underside of receiver.jpg

[m-4]

Welcome xarcher,
I will start with the fact that the chamber should be cast & bore slugged to eliminate all question. That being said, 7.7 is usually what you see with a .318 groove dia. & 7.8 with the .323 groove dia. Now seeing the rib stamped with the Magnum would lend me to believe it to be an (S) .323 as I have never seen a .318 marked magnum. What I would worry about more is the reloads you show (Norma brass & silver primers with an RWS 8x60S Magnum box). I think I would want to dismantle those reloads & reload knowing for sure what I was shooting through it! Proper scope with claw mounts can be accomplished by many of the good smiths out there however it is expensive. NECG does them as well as others.
Verify & enjoy your nice rifle.
m-4

[Axel E]

As the proofhouses measured the bore/ land diameter using cylindrical plugs in .1 mm increments, the bore of your rifle may have been as large as 7.899 mm. The original cartridge designaton "8x60 MAGNUM" on the top rib clarifies things: This was the pre-1940 name for the 8x60S, .323" bullet. The strict differentiating between I and S, as well as these designatons, were valid from 1940 on only.
Your rifle was originally proofed for the 8x60 S/Magnum by the Suhl proofhouse in 4/27 = April 1927, BGU proofmarks.
But you have the wrong ammo notwithstanding. A few years later the owner decided to have the rifle modernized/improved. He had it rechambered to 8x64S Brenneke and duly reproofed in 133 = January 1933, crown/R repair proofmark. Of course, at the reproof the rifle was again marked for Geschoss = bullet use and Untersucht = inspected for defects. 64 is the new case length, 15 gramm the conveniently rounded bullet weight of the 14.7g = 227 gr Brenneke Torpedo Ideal Geschoss, TIG, an early dual core bullet, advertized by Brenneke at 2720 fps.
Unfortunately they missed to alter the cartridge designaton on the rib then. Marking the cartridge name on a gun was mandatory from 1940 on only.
8x64S factory ammo is offered by Brenneke
http://www.brennekeusa.com/cms/h_home.html
and by Sellier & Bellot
http://www.sellier-bellot.cz/en/prod...tion/products/

[xarcher]

Thanks M-4. I am planning all along to dismantle the loads I have and start from scratch once I get the casting and slugging done. It might be a while though as I am out of town a lot. Depending on how that turns out, I only want to salvage the brass and go from there.

[xarcher]

Axel, thanks for the quick reply. The guy who referred me to this site specifically mentioned your name as one with a wealth of information. I see how your eyes just walked up the barrel to tell the story. So just so I get this right, it was born an 8x60S, converted to an 8x64, both with a .323 bullet. And thus the caliber markings on the rib are obsolete and misleading. Probably why I have the wrong ammo??? So assuming the slugging and casting confirm all of this, that explains why the few rounds of 8x60s ammo that I shot over 10 years ago fit the 8x64 chamber (loosely) and why the 323 bullet passed through the barrel.

So having said all of that, and since my reloading DNA likes to take over, would I be able to safely fire the 8x60s rounds that I have (after slugging and casting), thus fire forming the brass and then reloading with 323 bullets? Or should I buy and fire the factory ammo and save that brass for reloading?

Thanks

Jeff

[Axel E]

Forget the 8x60s brass for use in a 8x64S chamber! It will not headspace properly and after fireforming it will come out with a neck at lest 4 mm = .16" short. The best option would be 7x64 brass. Simply expand the necks to take .323" bullets. Second best may be .35 Whelen brass as the reduced necks leave a false shoulder for fireforming, but will be still .04" too short. Third choice: .30-06. May have headspace problems on fireforming and will come out a bit short too.
To avoid future confusion: Have the 0 in 8x60 stamped over with a 4.

[mike ford]

xarcher,
Axel is, as usual, correct. In my experience, 7.8 as often shows a .318 barrel as it does a .323( or .320 or .321). Slugging the barrel tells the tale. You will find factory 8x64 ammo very difficult to find, and since you are a handloader, that is the way to go. For brass, you can use 30-06 cases. They will be a little short( 2.49"vs 2.51"), but perfectly useable. If this disturbs you, or if you have a 270, you can use those cases(2.53", but will shorten a little in necking up. 06 will also,but not as much). It seems you can use 323 bullets, but to be sure the 8x64 chamber wasn't reamed with a reamer for a .318 barrel,I would check to see if a .323 bullet will easily enter the neck of a fired 8x64 case. If not, instead of using .318 bullets, I would have the neck opened up until the bullet will enter( assuming the barrel is .323, measuring with a caliper is often a couple thousandths "off", but the measurement is usually too small rather than larger). If you have 8x60 dies(or even 8x57) you should be able to use them by carefully adjusting them to "kiss" the shoulder of a fired case instead of screwing them down to the shellholder. You might not be able to crimp, but I seldom crimp anyway. Seating the bullets won't be a problem. For loading data, you can use data for the wildcat 8mm 06 as a guide. In my unsolicited opinion, both 8x60 and 8x64 are very good cartridges( in either bullet diameter). Enjoy your rifle, you are very lucky. It seem Axel and I were writing our last posts at the same time. I too would use 7x64 cases, but I understand that not that many people in the US , other than I would have a supply. Mike

[xarcher]

Thanks Mike. I am thinking about going the 30.06 case route, kiss the shoulder with an 8x60 die and move on. The neck will eventually stretch and the shortcoming will eventually diminish as I go through multiple reloads to tune the load. From what I have read it looks like the 8x64 can throw 190-ish gr bullet in the neighborhood of 2700 fps. That translates to north of 3000 ft lbs.

[m-4]

Good eye on seeing the 64mm designation Axel! I missed that in the picture & was going to suggest a new pic turned to that flat for picture quality. My bad, did not view the top series of pic's that clearly showed the rechamber!
m-4

[Axel E]

G.C.Nonte's 1961 recipe for forming 8x64S Brenneke brass, from The Home Guide to Cartridge Conversions:
Form this case from .30-06 in the following manner:
Expand necks to .35 (this would make them .35 Whelen, btw);
Size in 8x57IS die (8x60S will do even better) till bolt closes;
Fire form.
Don't forget the necking up step! If you merely resize the .30-06 shoulder all the way you will create excessive headspace, as the .30-06 case body length to shoulder is 1.95", while on the 8x64S it is 2.04". Firing cartidges with .09" excessive headspace will lead to case stretching and eventual head separation.

[Axel E]

Some pressure tested 8x64S Brenneke loads, using components available in America, from the DEVA handbook. CIP max pressure for the 8x64S is 3300 bar (piezo electric transducer).
Speer 170 gr / IMR 4895 53.2 gr / 2837 fps / max pressure
Nosler BT 180 gr / H 414 56.5 gr / 2831 fps / max
Nosler Partition 200 gr / H 4350 64 gr / 2706 fps / max
Speer 200 gr / IMR 4064 50.7 gr / 2640 fps / max
Hornady 220 gr / IMR 4350 59 gr / 2493 fps / max

[xarcher]

Thanks Axel. Since your post yesterday I contacted the 2 bullet manufacturers (their US reps) and they both said they do not import the 8x64 to the US. So Nonte's recipe for sizing is the way to go for sure. I have found a set of 8x60S dies and maybe I should look for a neck sizing die as well. To be honest, I prefer fire forming brass on all of my guns if it does not jam the round. It can only help with accuracy. Also thanks for the sample load formulas. Have most of that stuff on the shelf.

Thanks again. Jeff

[xarcher]

Axel, I found 8x64 RCBS dies available from Midway USA. These should work, right?

http://www.midwayusa.com/product/371...ProductFinding

http://www.midwayusa.com/product/548...ProductFinding