Help with loading the 8X58R Sauer

[Billkek]

Good evening. I am a new member and I wanted to ask if anyone is familiar with handloading the 8X58R Sauer cartridge. This has a straight tapered case using a .318 bullet. It is not the 8X58R Danish cartridge. I have a combination hunting gun by Miller & Greiss (16Ga top barrel with the 8X58R Sauer bottom barrel). The gun was just serviced by Mr JJ Perodeau and I would like to shoot it. I was able to buy some rounds from Reed’s Ammo a few years back, but they are hard to get. I have been reading a lot of posts and threads at the double gun forum and some other ones and have gotten about 4 reloading recipes. I have sourced some reformed cases from Buffalo Arms and .318 bullets from Reed’s ammo. I have not reloaded before, except 12 and 20 gauge shotshells a few years back. I understand I can use a chronograph to measure the speed, but how do you measure the pressure on handloads? Any guidance and tips on how to get started safely in this handloading endeavor would be greatly appreciated.
Thank you in advance. Bill.

[ligonierbill]

To answer your question, there is no way to measure pressure without some special equipment. The good news is you have some load data (the doublegunshop.com guys are very knowledgeable) and some actual ammo. Fire some of your precious ammo over a chronograph to establish a baseline. Now get a loading manual. It won't have data for you, but it will have lots of information on technique. Load a few rounds based on your "recipes" less 10% and run them over the chrono. Assuming nothing untoward (see your manual) work up in small increments until you are close to your commercial rounds. Be careful about what powder you use. Be sure it is one that has been tested and reported, not an apparently close substitute. Good luck!

[44 AMP]

My old (1972) Cartridges of the World has a brief entry for the 8x58R Sauer.

Says it is an obsolete black powder round found in single shots and combination guns, and gives the factory load as a 196gr bullet with an MV of 1690fps.

There are several powders that should be able to replicate that at black powder pressure levels, which should be safe in your gun.

The old book I have says it is about in the .32-40 class and the illustrations shows a rimmed case with a tapered body, and a straight neck.

There is one load listed using a Lyman 155gr cast bullet and 4198 powder giving 1700fps, but I won't list it here, as I have no way to verify it is safe.

Good Luck with your search!

[Billkek]

Thank you for your replies. The good think is that my gun was made sometime in the 20s and it is marked nitro proved. I welcome all your advice and guidance.
Thank you for your help.
Bill

[Unclenick]

For those curious about the difference between the two 8×58 cartridges, I am taking advantage of the generous permission we got from QuickLOAD's distributor to make occasional posts using that program's data.



I took a look in QuickLOAD, the interior ballistics program, and concluded the best powder for the most common bullet weight (196-grain jacketed bullet) was likely to be Vihtavuori N130. The trick is to find a powder for which the starting load (the lowest level charge you start with before working up while watching for pressure signs; your manual will cover this) fills the space in the case under the bullet by at least 70% (aka, the loading density). Below 60%, some powders start getting erratic in pressure, and 70% is usually used instead to add a margin of safety and allow for transportation vibration to compact it some. At the other end of the equation, you don't want a powder that won't burn reasonably well at the low pressure you have, so I didn't want to see too much unburned powder at the end of the firing event. N130 looks like a good compromise.

[Billkek]

Thank you. That is very helpful. Some of the members at the Doublegunshop German gun forum suggested loads with N140 powder and IMR4064 powder. How does IMR140 compare to IMR130? I have found IMR140 but it looks like almost everyone is out of stock on IMR4064. Thank you. Bill

[Unclenick]

In QuickLOAD's records (the cartridge is too old to be in current CIP or SAAMI standards), the peak pressure rating is just 31,900 psi. That means faster powders will burn better in it, like the IMR4198 mentioned previously as being part of a published load. N120 would match 4198 pressures fairly well. I went slightly slower with N130 because neither IMR4198 nor N120 can be loaded down to a starting load without going below 70% loading density (the portion of the space in the case that remains after the bullet is seated) in my software. N140 and IMR4064 are slower, still, and a larger amount of unburned powder will go out of the barrel with them, plus the slower powders are harder to ignite consistently. As it is, with all the empty space in the case (smokeless powders have higher energy density than black powder, so they won't normally have enough bulk to fill your case without going over-pressure), you may find you have to use magnum primers to get the best velocity consistency, anyway.

I know the gun is marked safe for nitro powders, but the old nitro powders, like cordite, didn't fill a case fully and weren't as high in energy density, so more case capacity was needed for more modest performance than modern powders provide.

I suspect the folks at the gun store looked at the size of your case and the caliber and thought the N140 and 4064 would be appropriate because most other cartridges that caliber with a case that size would use them. What they likely did not know is how low your peak pressure limit is. Those other cartridges of similar size and caliber have peak pressures from about 48,000 to 65,000 psi, and not just under 32,000 psi, as yours is. That's lower than 9mm pistol and magnum revolver peak pressures.

Note, also, I am basing the above on the 195-grain bullet. If you get a jacketed 150-grain bullet, then the faster N120 and IMR or H 4198 both outperform N130, and both give you over 70% load density for a starting load with the lighter bullet, according to the ballistics software.

[Billkek]

Thank you Unclenick for your reply. Is it a problem if the powder does not fill the case completely? In situations where you said for example the powder is at 70% capacity, do people use fillers to completely fill out the case or is it safe to leave it as is?
Bill

[Unclenick]

Try it and see. Fillers should not be required, but you will get more consistent velocity and pressure if you have a tuft of polyester pillow ticking holding the powder back over primer vent (flash hole).

[stagpanther]

Try it and see. Fillers should not be required, but you will get more consistent velocity and pressure if you have a tuft of polyester pillow ticking holding the powder back over primer vent (flash hole).

Interesting--never thought of that--I'll have to try that some time. I've had a couple of hangfires in my time but usually with high capacity big cartridges that I was downloading; it seemed to me that if I could hear the click of the trigger and there was a perceptible delay in ignition I was getting close to hangfire danger zone.

[Billkek]

Hi members. Today I shot for first time my combination gun of 8X58RSauer with some ammo from Reed’s Ammunition & Research I had bought a few years back. These rounds are made with reformed cases of 303 British. I fired 8 rounds of 175g soft point .318 bullets and 3 of 200g soft point bullets. Of the 8 rounds 175g bullets, 4 cases splintered near the mouth of the case. Also, I can see some discoloration near the mouth of the cases that did not split. The cases are very thin at the mouth. What do you think the cause is? Any help would be greatly appreciated. I have pics of the fired cases but I am not sure how to post them. If you can assist me with that, it would be great. Thank you, Bill