7.92x57 JS load question

byelogvardetza

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Mobuck

That powder is way too slow burning for anything close to optimum performance in the 8x57. Use it if you like it but you'll run out of room before you get a reasonable velocity.

Tailgunner1954

At a guess you have a severly worn throat. The H-1000 is burning slow enough to get the bullet into the rifling before the pressure builds, but the amount of it that your able to get into the case isn't enough to get the velocity up where it should be.

Round nose bullets might help (the ogive diameter is closer to the tip), but the real answer may well be to screw on a new barrel.

byelogvardetza

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Tailgunner1954

Have you asked LW what they think?
Chamber cast to see if the throat was cut oversize?
IOW I personaly wouldn't be a happy camper and would be ringing the barrel makers and gunsmiths phone off the hook

OTOH if the prefomnace is acceptable to you, than shoot it.
As far as increasing the charge weight, as your in "uncharted waters" with that powder, go up in small increments and shoot 10-20 rounds at each level. If any of the test cases looks 'hinky", than back off (your looking for signs of eratic pressures)

Mobuck

I would not load more powder than will reach the base of the case neck. You can vibrate or tap the case a little to settle the powder to reach this level but compression over 10% would not be advised. The 198 grain bullet is pretty long and extends into the case significantly resulting in associated powder compression. Over compression may hinder powder ignition resulting in some strange pressure deviations.

sandwarrior

quote:Originally posted by byelogvardetza
TG - its a brand new walther-lothar barrel, no worn throat at all.
Mobuck - sure, faster would be better, but optimum velocity isnt my biggest concern since it will be a 100-200 yd. rifle. Slow and accurate are fine, but I'd like to know if others have bumped it up to a "compressed load" or if that risks unsafe pressures. I even asked Hodgdon, but they didnt know and gave me the generic .318/.323 low pressure data for a 24"bbl (fast burning powders).
thanks, more input is appreciated.


byelogvardetza,

Yes, I did some loading with some 200 gr. bullets w/H1000, Seems like I went compressed and loaded 57 gr. It still only gave me 2500 fps. I can get 2600 fps with 50 gr. of IMR4064. I can't speak for the pressure of the H1000 but the 50 gr. of IMR 4064 is over the ({Pathetic}) pressure cap of 37000 CUP (around 44-45k psi) The round can take 52k psi. and will show pressure like any other Mauser case (which are all under loaded in all the books now). If you decide to move up with the H1000 you can load it until it is compressed yes, As you seem to have picked up you're doing it the best way at least by using heavy bullets and a long barrel. See what you get by chrono'ing it if you know someone with one.


MY USUAL WARNING ABOUT WORKING UP FROM A SAFE LOAD ALWAYS APPLIES.
I have typically worked up in standard grain/partial grain increments. But, Rocky Raab suggests going up in small percentages. When worked out mathematically it makes sense. Hopefully, he may come along later and give a response to this. nononsense as well. You can e-mail either of them if you wish to kind of speed up the response time.

-good luck with this.

byelogvardetza

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jaegermister

from my experience h1000 is too slow burning to completely consume in 8x57. Often times when experimenting with new loads I place a white poster sheet flat on table out in front of muzzle. After firing look for un burnt powder. Most often when you find un burnt powder your chronograph will show you are going no where with velocity. i have no problem with 4895 in 8mm.

byelogvardetza

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sandwarrior

byelogvardetza,

What you are seeing then is typical (non-typical?) harmonics at work. I've always had good luck shooting the IMR 4064 in the 8mm case. From 4895 which is relatively fast for the case you get the big groups. What I'm seeing here is your barrel likes a slower powder. But, needs more oomph. So, what I'll recommend is VV 560 which is about the same speed as H4350 but high pressure. Re-22 or Re-25. Both are slower but higher pressure. Re-22 is just faster than H1000 and RE-25 is just slower.

Before you go to the high pressure powders, you might try H4350 and AA3100. See what they do.

Anyhow, start loads for each powder is:

H4350/AA4350 is 50 gr.
H4831SSC 51-52 gr. You should be able to work up to a compressed load with that as well.

AA3100 is 52-53 gr. Make sure you don't confuse this with IMR3031. AA3100 is a much slower powder.

Ramshot Magnum 49 gr. (use magnum primer)

VV560-50 gr. to start.
RE-22-start @ 49 gr.
RE-25 Start at 53 gr.

Use a magnum primer with the last three.

WHAT WAS GIVEN HERE WERE START LOADS. YOU WILL NEED TO WORK UP TO A SAFE LOAD FOR YOURSELF.

-good luck, hope these help.

jonk

I have found that a case full of slow burning powder often does indeed produce excellant accuracy. I regularly use surplus .50 machine gun powder in my 30-06, full to the base of the neck with a mag primer. It's a fairly common way of loading low velocity high load density loads with cast bullets.

I've had very good luck with H4831 and IMR 4831 in the 8mm- again, I just fill the case. It is at the top end of slow burners that you'll find data for but of course, check this for reference for start loads.

I've also done well with 4350 and H 414.

If I find an accurate load, I don't much worry about velocity. Some of my most accurate loads are even slower than yours- around 1400 fps. If I'm just punching paper, who cares how fast it is going? It gives the added advantage that while milsurp rifles often shoot high, at a lower velocity they're right on.

byelogvardetza

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sandwarrior

quote:Originally posted by byelogvardetza
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Anybody with a clue as to what's going on here? Poofed posts but not thread?

GONESHOOTING

quote:Originally posted by sandwarrior
quote:Originally posted by byelogvardetza
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Anybody with a clue as to what's going on here? Poofed posts but not thread?
Same here, all I get is *****[?][?][?]