8mm Mauser JS

[kimbernut]

I am beginning to study up for loading 8mm Mauser JS(.323 diameter). Using IMR4064 I have noticed that most reloading manuals start loads are around 35 grains powder for a 170 gr.SSP(+-2000 fps) while the Speer manual starts at 45 grains for (+- 2500 fps). Is this because of a fear of liability issues of someone blowing up a turn of the century Mauser(.318 diameter) or is this a case of Speer loads starting hotter than others just because? All opinions/advise appreciated.

 

[ocabj]

Yes, .318 and .323 bore difference is one reason why some load data is lowered.

Manual usually have info regarding each caliber and reasonings behind their load data.

 

[cracked butt]

*warning- maximum load*

One of my reloading manuals gives a maximum of around 51 gr of IMR4064 for a 170 gr. roundnose.

I personally find that using a 170 gr Hornady interlock round nose bullet with 50 gr of 4064, federal 210 primer to have good accuracy in most of my 8x57 rifles, including a Yugo M48, Persian 98/29, Turk M38, and a kar 98, the only rifle of mine that dosn't seem to like it of mine is a 98/22.

The recoil is pretty stiff, but I get no high pressure signs in any of my rifles, and my rifles are in good condition and are of safe headspace.

If you are shooting a mauser rifle, I would start at the bottom of the laod range and work up in .5 gr increments- From what I've seen with mausers, they may look wildly inaccurate at one loading and be very accurate with another.

 

[cracked butt]

As far as disparities in loading information goes, some manuals are overly conservative and assume that some people are going to load for the wrong rifle or a worn out rifle. I bough a set of Lee 8x57 dies a few years ago and found that the load data sheet pretty much maxes out where the Lyman manual begins.

 

[Okiecruffler]

I'm not posting recipes, because I have no control over who loads what or what they shoot it out of, but a few years ago I got real creative with some reloads and a M48A. I will say this, the potential of this round in the correct gun is incrediable. The 8mm mauser has been limited in American factory loadings due to all the older guns still out there.
It goes without saying, but I'll say it anyhow, be cautious, look for all the signs. And remember that sometimes the hottest load isn't the best load.

 

[sumpnz]

WARNING - This is nearly a 100% loading. Work up to it carefully.

My FFL cooked up some handloads for me for my Turk T38. Using Remington brass, CCI 200 lg rifle primers, and 52.0 grains of AA 2520 we were able to launch Hornady 150 spire points at 3007 fps (95F, 2500' elev, windy but clear). No signs of excess pressure. No problems with a sticky bolt.

As a comparison, my Turk surplus ammo was chrono'd the same day (but at 98.6F) at 2994 fps for a 154gr FMJ. This ammo had quite a bit of flow around where the pin struck the primer. I also had a sticky bolt with this ammo, which indicates that it is a bit softer, and therefore flowed more than the new Remington brass.

 

[Clark]

"Speer 12" lists loads for the "8mmJS" and has 50 kcup loads, not per SAAMI, but per European standards.

AA has loads for the JS up to 58,200 psi:
AA 8mmJS loads PDF

My 1903 Turks, 1938 Turks, VZ24s, 98/22s, 24/47, K98, ect are 8mm JS and I load them up to 30-06 like performance.

 

[kimbernut]

Thanks,all. Your input has helped tremendously!

 

[Quantrill]

I, too, am preparing to load 8mm Mauser for the first time. The info that I have is that American manufacturers of 8mm ammo (Rem., Win., etc) load the cartridge down (30-30 Win. level) in case some fool uses it in a "J" bore (.318). However both RWS and Norma load their 8mm to the higher levels (30-06 level). I would imagine that the various reloading guides do similiar things to prevent a catastrophy. Please keep us informed as to your results.It has crossed my mind that this rifle could turn out to be a cast bullet rifle only. Quantrill

 

[Clark]

I was learning how to handload, and working up a load with an old 1903 type Turkish Mauser I bought at BIG5 for $50.

The IMR website says: 170 gr, IMR 4895 33.5 gr, 2145 fps ,37,000 CUP
http://www.imrpowder.com/data/rifle/8x57mauser.php

So I started out at 30 gr with 200 gr bullets and worked my way up.

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.

So I worked my way up with white knuckles, thinking that the gun would blow up at any minute. Each round was dramaticly scary, as each round got louder and kicked harder:
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50 bolt a tiny bit sticky
51 blot more sticky
52 bolt very sticky

Then I worked out that I got good accuracy and 2630 fps with 47 gr.

Then I read a different load book, that validated my load.
If I had seen that load book to start with, I could have avoided all that fear at the range.