Hello guys. I've been reloading my 8x57 with 56g of 4320 underneath a 180g Nosler Ballistic Tip. My chronograph is indicating an average MV of 2995 fps. This is obviously WAAAAAAY above published max powder load and MV.

I've seen absolutely zero traditional "signs" of pressure: no stuck bolt, no primer problems (though they are very flat), no indication of the indentation mark on the case head.

Still, it does make me a little, shall we say, uneasy. Is the 48A up to snuff here? Just wondering if anybody here is shooting loads this hot in their Yugo.

The load is wonderfully accurate, by they way. I have a Leupold scope mounted on the rifle. Thanks. 8mmFan

Well, you went 6 grains higher than I had to balls to go!

Good luck...

Did you stop because you experienced signs of high pressure, or because you felt that you'd gone far enough beyond published loads? I ask because since I didn't see any pressure signs, I just kept going.

8mmFan, you can have seriously excessive pressures with no visible signs on the brass. Check out the info here: http://reloadingpro.com/

Ricochet is absolutely right. Typical excess pressure signs typically do not start until you're well beyond safe limits.

Just for a ballpark example, a grain of powder in an '06 size case corresponds to about 50 fps and 2000 PSI. If you ramp up until your primers come loose, you're at about 75,000 PSI. If you then back down a grain, as some people then do, you're running at about 73,000 PSI. That's a lot.

CIP rates the 7x57 at 49,300 PSI. That converts to roughly 45,000 PSI in the ANSI/SAAMI system. Now with that said, it's probably a ridiculously low spec. People put 308 and 30-06 barrels on the newer milsurp Mausers, and run them at 58,000 PSI or more all the time. Still, I think you're running at some really high pressures.

8mmFan

Just for fun, I ran your load thru my Quickload program. I assumed a 24" barrel. The predicted velocity was 2957fps (pretty close to your measured velocity) with a max pressure of 69443 PSI. The max pressure according to SAAMI is 35000 PSI. According to CIP, the max pressure is 56564. These SAAMI and CIP pressures references are as shown in Quickload's cartridge database.

Now I'm confused.

I looked up 7x57 in the SAAMI manual, and it's rated at 51,000, but the 8x57 is rated at 35,000. I always thought the 8x57 was a higher pressure cartridge, close to the 30-06 in performance, and that 8mm Mausers were the preferred vehicle for a custom rifle. ???? Hasta just be a SAAMI incosistency ???

Anyhooo.... 69,000 PSI is braver than I am, and that's a very believable number. If you figure ROUGHLY 2 KPSI per grain, you're going to need to back down ... ummmm... 6 grains or more. Seems that someone mentioned that number once before....

I would say 50 to 51 gr's of 4320 would be a max load in most 8x57's I've had.

Supposedly the low SAAMI pressure for 8x57mm is out of concern for firing .323" bullets in .318" barrels, and for possibly weak old M88 rifles.

Are the pressure figures related to the strength of rifle steel in general, or are they tailored to each individualcartridge? It's obvious that I'm over the listed pressures, and I'll back off. But what I was wondering most was, where does the strength of the M48 action stand in relation to many of the other actions that the SAAMI organization may have considered when it determined the max pressures? It's certainly stronger than some K98 manufactured in 1944-45, when the Germans' war production wasn't at it's best. Probably stronger, too, than, say, a rifle manufactured for the same cartridge in 1905. So, do those pressures apply mainly to the lowest common denominator, in terms of strength, in any actions that might be encountered in the universe of the 8x57?

Wouldn't there be different standards from one make of rifle to another, especially with regards to all the Yugo/Argentine/Mexican/Chinese/German MilSurp rifles out there? Sorry if I'm beating this to death. I'm probably just trying to "whistle through the tulips" into thinking this load is safe in an M48A. 8mmFan

Some Turk 8mm ammo fired a 196 gr bullet at 3000 fps. With that stuff you get a hard bolt lift.
You are pushing the evlelope. You will not "Blow up the gun" but you have little margin for variables.
What will probably happen is that the locking surfaces will beat back and the bolt will stick.
98's will stretch, and be ruined before they blow. Commercial US ammo is loaded to 32 special levels
but people that don't know that will brag about what a good deer killer their 8mm is.
Good Luck!

Getting a good solid "fix" on allowable pressure on a milsurp is not easy... different manufacturers, slightly different designs, different materials, as you have said.

There are a lot of 30-06s and 8mm-06s floating around, built on Mauser actions. Evidently, recent Mausers will handle 60 KPSI. I sure hope so, because there is a custom 06 on a Mauser action in my cabinet.

Now what about my Swedish M96? Older action. But Swedish steel had naturally occurring manganese in it, which made the steel tougher than heck. So, in that case, I don't know. I just run it at moderate pressure.

8mmFan, I would not dare to go any higher - it's better to see no pressure signs than to find them in your face. I would reduce the load, even if it performs great, because unfortunate conditions (hot summer days) might end bad.

Denton, you'd better not rely on "steel tougher than heck" - several posts on other boards say the Svedish Mauser is not so strong as the one produced in or by Germany.

I blew up a Mauser by perfect stupidity, and I know by doing: the Swiss K31 is extremely strong as I used N110 instead of N140: stiff bolt lift, no more.

Now you know what kind of reloader I am.

What I've read from others who know a lot more about it than I do is that the Swede may be strong enough to handle the full pressures of hotter modern loadings, but the action's not well designed to safely handle gas if a cartridge case does let go.

The mod. 48 Yugo has what is known as a saftey breeching system which allows slightly more of the cartridge to be supported or surrounded by the barrel as opposed to a standard 98. This, however, does not make your load safe. My .02.....Roger.

I cannot agree with Carcano on the "weak" K31 action.

He refers to a report of a wrecked K31 where the author tries to find an explanation why. Between 11 reasons listed, only SEE or double charge are of major importance.



The shooter claims the load was 23.7 grs N110 behind a 170 grs bullet. QL shows more than 140.000 psi for that load doubled (47.4 grs). As the load density exceeds 100%, the reloader should have seen that something was not properly loaded.

Here you find a picture of the modified K31:



http://www.hunt101.com/showphoto.php?photo=96303&sort=7&thecat=500&password=



Compared to this, my load of 42.3 grn N110, yielding "only" 105.000 psi, was 40% less, but not mild.



I ask you, Carcano, is this really a weak action ?

Very interesting K-31 photo! Someone else(Guisan) posted a blown 31 action on a different(Swiss) forum with no info other than the pic. Most likely the same action as in this pic. Waitaminute or Carcano, do you have any other links or more info you could share about the particulars? The Swiss (unmodified) actions seem to have an excellent safety record. I've found only two reports of any 31's having an action failure. Does anyone know of any. Both failures have been in modified 31 actions. The other 31 action was only a reported cracked reciever with no explosion or pieces flying. This was in an English proof house test, quite some time ago, after modifying a 31 action to 308 Win. For blown cases, I think the biggest knock for the 31 is it doesn't vent gas from the shooters face as well as the 98 mausers. For bombs going off in ones face, does it matter if it is a Swiss 31 or a mauser 98 at 90K, 104K, or 140K. You shouldn't be anywhere close to those kinds of pressures. I believe the Swiss have always forbade reloading for their service rifles. The Swiss auto loader (57) like the Cetme and others that have a fluted chamber wreaks havoc on any brass. Reloading ammo from fluted chambers would be risky bussiness for any cartridge. As a Swiss buff, I'd sure like to hear more about wrecked Swiss actions from anyone!!! Best Wishes All

I agree that pressures like those in question would very likely also have wrecked a M 98 receiver, in some way. This would argue against my proposition. Also, I may have been influenced by the commonly held and repeated opinion here in Germany that the K 31 action is weak - an opinion need not necessarily be right (after all, the Carcano has a bad reputation and it is one of the strongest military bolt actions ever built).

Still, look at the flimsy metal of the receiver and the fragile receiver ring, and then tell me how comfortable you'd feel now that you have actually *seen* the dimensions of the broken parts ?

Regards,
Carcano

Carcano, I know that the numbers of Swiss actions is considerably less than the numbers of mauser actions. Still, I know of only two failures in the 31 and plenty of 98 failures. The Swiss Schmidt-Rubins have been the subject of much misinformation and inaccuracies. It perpetuates itself. Yes, I still feel comfortable shooting all of my S-R's. Some people will always push the pressure envelope. I try not to. I do like to follow MV's with my chrono as powder weights increase. Soon, I'll be using a strain gage also. I'd still like to find any examples of S-R failures modified or not.

Lonniemike: Since you know of "plenty of failures with 98 actions) could you share yourknowledge.
Eg. What let go?, Did the bolt stay in place?, Was the shooter, or anyone else injured?, What
happened to the stock?. This information is too valuable not to share.
Thank You!

8mmFan,

The Yugo 48A is an 1898 large ring type design.

Because of that, I would treat it as stronger than the brass for any .470" base cartridge, like 8mm. It has a gas venting chamber in the bolt and a third safety lug in the rear. IMHO, this is the best rifle design available.



In 2001 I shot 200 gr. bullets in a 1903 Turk [It is also a '98 type design] and got a slightly sticky bolt at 50 gr. and very sticky bolt at 52 gr. IMR4895.





Yesterday at the range, with yet another 1903 Turkish Mauser with "1936" written on the crest, I was shooting 8mm 200 gr. Sierra Match Kings with 47 gr. IMR4895 for accuracy.





So I felt confident yesterday shooting 47 gr. for accuracy would give me a useful load that has plenty of safety margin for chamber temperature, component variation, and my own handloading consistency. I don't want a stuck bolt when I am hunting.



I got 2618, 2633, 2649, 2623, 2650, 2626, and 2638 fps.



I sighted it in and shot one 5 shot group, and it was sub moa at 100m! That rifle deserves a second trip to the range with some different powder charges, bullets, and seating depths. I am very encouraged about that $50 Turk.



--

A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

Hi Clark,

Thanks for confirming what I suspected: that the M48's & M48A's are terrific actions and, indeed, terrific overall rifles. I really, really like these rifles. The old-school craftsmanship evident in all of them is impressive. They are made with the the high-quality workmanship that the old gunmakers could afford.

That's why I feel OK pushing the pressure a bit. I took a page from Bob Hagel's reloading books and decided to push the envelope a bit. Nobody would dispute that Hagel loaded his rifles hot and regularly took cartridges to the edge. His 8mm Mauser was no exception.

I am primarily a hunter, not a target shooter, and hunting's what I have in mind when I reload for one of my rifles. With my scoped 48A and 8mm 180g Nosler Ballistic Tip bullets (which are constructed much more strongly than the BT's for .308 and below), I would not hesitate to shoot any North American animal and anticipate a one-shot kill, and that includes Brownies if the right shot presented itself. Still, if it was a hunt specifically for brown bears, I'd load up with the 200g Partition. The 180g BT's are absolutely devastating on deer.

As stated above, I shoot the 180s at an average MV of 2995 fps. That 180 at 3000fps is not very far at all behind the 300 Win Mag. The accuracy is astounding: as long as the barrel is cold or "cool" (a normal hunting scenario assumption) it will group shot after shot, and I mean shot after shot after shot, in an inch. Let the barrel heat up with all that wood and metal around it though, and accuracy becomes a joke.

It's not a sentimental gun for me: I have more than one. As long as the gun doesn't BLOW UP and hurt me or someone nearby, I don't really care if it's "ruined" over the long haul, with the stretching mentioned above, for instance. I'll just junk it.

When the weather warms up a bit, I'm going to start working up loads for the 200g Partition. I anticipate pushing them as well. I'd love to take those 200s to 2750 fps or so. 8mmFan

8mm....

In round numbers, you can expect your chamber pressure to go up about 70 PSI for each degree F your powder temperature is raised. You can expect it to go up 150-200 PSI for every degree F your chamber temperature increases.

We'd like to keep you as a poster on this board... and we would rather not have to call you Lefty.

What you're doing will become even more dangerous as temperatures warm up.

Clark...

1 MOA?? Why can't I get a Yugo or Turk that will do that??? Lucky pick at the gun store, or lots of work since you bought it?

Denton:

Thanks for the kind comments. I'm not going to push the rifle any further; the only time those 180's will ever be fired that fast again is when sighting in or hunting. A few rounds at most. I usually fire cheap Turk ammo when I practice. Incidentally, those loads were developed in the heat of this summer. I'll never know, because I won't try, but I bet this rifle could push the 180's to 3100-3150 fps. Like I said, I'll never know.

As for getting your Yugo or Turk to MOA: have you ever fired your rifle, and then let it COMPLETELY cool down before firing the next round? I bet you'd get your MOA rifle if you did. This is what I do with mine. I fire one, or sometimes two, shots and then completely cool the barrel down before firing the next shot. The rifle is then better than MOA, and I feel that this more closely replicates hunting conditions. I think that the extensive wood and metal on the military configuration Mausers keeps them from being MOA because the barrel heats up,touches wood, and then goes haywire. 8mmFan

You bought 20 of them!??? No wonder you got yourself a good shooter, especially after all that work.

I bought one, and grafted a Remington '06 barrel on it. It's a beautiful gun, but I'm not in a hurry for another project that big.

Ran into a friend at the range the other day, and he had a Turk that he had really cleaned up to look nice. He did some really super work on the stock. He was having a real bad day, because it was shooting 4-5" groups at 25 yards. I showed him how to float the barrel, and it settled down to about 1 1/2 inches at 25. So he's feeling better. I'm going to show him how to shine the sear, and then we're about out of things that I have done at home. The crown looks good. What would you think would be the next thing to do? Lap the lugs so they engage at the same time?

A rifle that must cool down is of no use to me. My hunting rifles MUST be able to place 3 rds in less than 1" at 100yds, with the 1st shot from a cold clean oil coated bore, and the next 2 fired as fast as I can chamber and fire the rounds. I have a .270 win on a M98 that normally does less than 1/2 moa for this test!

It always is a suprise how many people can shoot sub MOA groups with 98 Mausers using open sights.
It is really an age of miracles.
Good Luck!

majorcalibre,

I'm with you on this one, I'm a good shot, (army accredited marksman) but I still have to fire 3, sometimes 4 shots to drop an animal - it's the real world, so many variables. Sometimes it's messy, and not at all like in the magazine articles. I sometime wonder about how much hunting people who insist on MOA accuracy actually do?

...from an oily bore...



Congratuations, Major Caliber !





To find out your real name, it only needs to look up the winner of a top rank LA competition.

Actually, my Swedish Mauser will do sub-MOA three-shot groups at 100 yards. That's with iron sights... Mojo, not open. That requires a bench rest, and a calm day. And I'm not much of a hunter... you'd get hungry eating what I bring home.

Three or four shots to drop an animal? Jeez, what kind of animals are you shooting at? :-)

With a 24" barrel it would take in excess of 70,000psi to get anywhere near 3,000fps from an 8X57 with a 180gr Ballistic Tip!



Even with a 28" barrel it would be over 62,000psi!



I believe the M48 Yugo has the shorter barrel does it not?



I would say that anything much over 2,800fps from an 8X57 with a 24" barrel (with the 180gr BT) would be "pushing it".