8mm Mauser reduced loads

[EMT_stuart]

I currently have received some H4831SC and H1000 powder, along with a case of 150 gr Sierra .323 spitzers.

I was hoping for a bit less recoil with these lighter bullets, and unfortunately, these two powders were the only ones I could find locally. Does anyone have any advice for this particular set of components? Thanks.

 

[Swampman]

DO NOT use slow burning rifle powders in reduced loads with jacketed bullets!

Google, "Secondary Explosive Effect" for information on why this is a bad idea.

Both of these powders are a bit slow for 150 grain bullets in the 7.92x57, but if you look around, you may find some safe full power loads.
Don't expect velocities as high as you'd get with more suitable powders.

 

[NCsmitty]

It's likely that you will not find many conventional manuals that has loads for your 8x57 using those powders, especially H1000, it's just too slow burning. You're really wasting powder trying to make them work.
Medium burn rate powders like H4895 work quite well in the 8MM Mauser, as well as others in that burn rate, but as you mentioned, those powders are in short supply.

Here's Hodgdon's reloading site data to compare loads.

www.hodgdon.com

Here's a link to reloadersnest site that has a couple loads listed using H4831, but it limits your potential greatly, and the 8x57 deserves better. The slower powders work more efficiently with heavier bullets.

http://www.reloadersnest.com/frontpage.asp?CaliberID=78


NCsmitty

 

[Kernel]

Both those powders are way, way, to slow. They’re more appropriate for heavy bullets in a big belted magnum.

Even if you filled the 8x57 case clear to the top the problem wouldn’t be high pressure, it would be low pressure. Might be so low as to not properly expand the case which could lead to a high bolt thrust, and other problems.

One of the best powders for all-around reduced rifle loads is 4895. Try to get you hands on some of that.

 

[EMT_stuart]

Thanks for the input, guys. I found a recipe from Reloadersnest.com that uses the same bullet and primer I have in 8mm Mauser. I'll go ahead and give it a shot; 1,998 ft-lbs doesn't sound like it would damage my 1888 Commission rifle (yes, it has an S bore).

 

[EMT_stuart]

http://www.reloadersnest.com/detail.asp?CaliberID=78&Powder=Hodgdon+H4831&LoadID=5696

This is the load I am considering trying. However, I filled up one of my cases with 50 grains of H4831SC, and it came very close to the shoulder and nearly filled it up. And that was still shy of the suggested load. Thoughts?

 

[NCsmitty]

Thoughts?

You can see that besides being a poor choice for performance, there are other issues such as requiring a compressed load at that charge level. Compressed loads are not normally a problem, but can be a pain to load, and I try to use powders to avoid compressed loads.
As mentioned, these slow powders should not be used in reduced loads for the possibility of the secondary explosion effect, or SEE.
You can sort through this site for the topic.

http://www.reloadammo.com/liteload.htm


NCsmitty

 

[Mobuck]

If you value your face or rifle, I'd suggest you just wait until you find some IMR4895.

 

[TenDriver]

IMR 4064 is another good 8mm powder. We worked up to 50 gr in a friends rifle, both him and the gun seem to like it. Personally I'd load to the min with that powder and see if it gets you desired results. I have loaded under the min load with this powder in .30-06 with good results (not that I recommend doing that).

 

[Swampman]

Stuart:
I was unaware that you were loading for a Commission rifle.
Those old rifles, some still with .318 bores, are the reason SAAMI set the max pressure on 8mm Mauser so low, @37.000 psi IIRC.

H4831SC is probably a pretty good choice for loading 8mm in an 1888 model. I know the Germans converted them to use the 1905 "S" loads, but most (all?) Commission rifles are at least 115 years old and 19th century steel wasn't made to the same standards as modern steel.
In addition, those actions weren't designed to safely handle escaping gas from a ruptured case like the 1898 Mauser was.

I don't think I'd trust a load on Reloadersnest unless I was able to verify it by a couple of other sources.

I feel that the slow pressure build up and low max pressure that you'll get with H4831SC, combined with light for caliber bullets like your 150 grain Sierra's will probably be almost ideal for loading safe, lower pressure ammo for your 1888 Commission Rifle.

Just make sure to use good quality cases and check them for incipient case separation before each loading. I'd probably limit the cases to a maximum of three or four reloads.