5.6x61 vhse Rich Mahrholdt&Sohn-Innsbruck info welcomed

[Kiwi_bloke]

Hi guys

I'd Be real careful about slow loads in this calibre. That's where this business of secondary explosion effect got started. I have published vom Hofe data here, but the text is in German. There is also an old issue of Wolfe's Handloader, (or Rifle? We're just putting the house back together after carpeting, so I can't put my hand on it immediately), that had English language and US style loads. I would stick to those loads, those powders, the right type of primer and I wouldn't load any powder that, using any recipe, didn't at least get past the height of the lower shoulder, preferably more, with 100% being ideal. If it doesn't substantially fill the case, look for another load. That secondary explosion thing is supposed to be about the primer flashing over a light load lying down and not making a seal, and the flash igniting the powder column both ends to meet in the middle. (though there are other theories too about some substituted French powder causing it in vom Hofe ammo, also weak firing pin fall has been implicated in some explosions. It has also happened in .38 Special. I think it is more about what you do, not what rifle you do it with, but "give a dog a bad name", as they say).

Accuracy with my Roell Mauser is 7/8" at 100 yards, maybe a bit less as I usually measure from outside to outside, not centre to centre.

The HH case is Horneber Huelsen. I don't recognize the other one. Might be a Norma one from some years back when they made them on contract. A European ammo collector would recognize the headstamps.

Re the M1908, a late friend of mine had an English-made rifle in 8x57 Mauser but it had head-spacing issues. His gunsmith turned the barrel about a 1/4 turn and made it into an 8x56 M.Sch. It looked like crap because the sights and etc., weren't blued underneath, so there was a big square silver blank where they had been. I sold it to someone for Walther's widow and that person, Tony, reset it back where it should have been. So assume nothing about markings!

[Kiwi_bloke]

The article is The Amazing 5,6x61 vom Hofe by Al Miller in The Rifle January-February 1971. It covers rimmed and rimless. Al was the editor then, I think. If you search Wolfe Handloader, you should find their website. Look for the back-issue section for Rifle. You may need to download a digital copy. Or I can scan this one if you send a PM. The staff there are real nice people, so try them first.

JC Munnell also wrote about it. I think in The Accurate Rifle magazine. I only have the draft, so I don't know the issue/year. Lots of loading data in that and case forming info.

[mike ford]

Kiwi_bloke,
That is why I recommended to use a medium burning rate powder in the 3000 fps loads, back on page 2 of this thread. This problem is hard, if not impossible, to duplicate; but I don't want to take a chance.
Mike

[Diz]

KiwiBloke brings up the interesting topic of secondary explosive effect. I can only speak to over forty years of experimentation in reloading and I have witnesses some unusual events. The phenomena of S.E.E. has never been one of them that I could be sure of. I prefer the slower powders for the precise reason Kiwi mentions and that is loading density. It is much easier to get a 100% fill with these than the quicker powders before pressure becomes an issue. Certainly, not all powders are alike in their burning characteristics, nor is every cartridge the same or bullet design and this is where things can and do go wrong. I believe that instrumentation is the key to understanding and then adapting scientific method to load development is the way. I use an RSI Pressure Trace to confirm theory and find it very much more reliable than chronograph numbers when doing load development. I don’t want to belabor the point and only advance what works for me and why I always place a disclaimer in all my work. Not completely trusting data especially unpublished is always prudent.

I would highly recommend to anyone really interested in learning about S.E.E. to read “Firearm Pressure Factors” by Wolfe Publishing. This is a compilation of a number of technical articles about the phenomenon. I especially recommend a visit the Recreational Software Inc. site at:

http//www.shootingsoftware.com

There you will find actual traces showing the effect of what is believed to be S.E.E. and technical discussions regarding them.

Thanks, Diz

[Kiwi_bloke]

There was a detailed article on Secondary Explosion Effect in an old Handloader magazine. I haven't actually seen it, just the reference to it. If I find the issue number again I'll order it. I think it could be quite enlightening. However from conversation with Lutz Moeller of KJG-Munition, I'd suggest loading anything less than about 90% case capacity in this over-bored vom Hofe round will court Murphy's Law.

Now, about powders: Mr JC Munnell, writing in The Accurate Rifle writes:

"(about) loading for over 150 different cartridges... (and in regard to the 5,6x61SEvH): "As is to be expected for a cartridge with a high powder capacity to bore ratio, the slower-burning powders are called for. The various 4831's and 4350's work fine, and I would expect H-1000 and Alliant Rl-25 to be excellent. Even Accurate 8700 was not too slow for this case".

He used reformed 9,3x62 cases and also Gehmann 5,6x61 cases which had about the same capacity. All the info I have regarding this cartridge refers slow powders. Indeed, if you look at what is recommended in published data and where it sits on a burning chart, it is not far from falling off the bottom end!

The published loading data I have, uses H4831, IMR 4831, IMR 4350 and H870 powders. The latter did not achieve anything like predicted velocities, and at any rate it is discontinued now. I even tried to use a custom Lee-Factory Crimp die to get pressures up. The other powders I have just listed, all from published data, all performed just fine in terms of the velocity reached.

Apart from his article on the 5,6x61SEvH, Mr Munnell wrote a series of articles on metric cartridges and their use in Drillings, sporters, break-opens and the loading for them. They should be required reading if you have one of the lessor known metrics, for instance on:

The 8x68S, (The Accurate Rifle March 2002),
the .30-06! (Precision Shooting August 2006),
the many 8mm European sporting rounds, (Precision Shooting July 2005 & Nov., 2005),
the 8x72R,(The Accurate Rifle Oct., 2001),
the 9,3x72R, (The Accurate Rifle Oct 2003),
9,3x62, (The Accurate Rifle May 2002),
the 9,5x57 M.Sch., (Precision Shooting Sept., 2005),
9,3x74R, (Precision Shooting Jan., 2007).

[mike ford]

Kiwi_bloke,
In the case that velocity needs to be held down to a lower speed( say about 3000 fps or less) due to bullet limitations, what were Mr.Munnell's recommendations?
Mike

[Kiwi_bloke]

Rifle Magazine, Jan-Feb 1971, "The Amazing 5,6x61 vom Hofe", by Al Millar states, "Hodgdon's 4831 delivered the most consistent accuracy in both guns". He was shooting 70-gr Barnes bullets at 3,679 fps out of a Mauser '98 action and measured velocity 10 ft from the muzzle using a Oehler Model 10 chronograph.

The rimmed case single-shot he loaded with 4831 and 4350, (it would seem he still means Hodgdon, not IMR), to an estimated 3,400 fps. He considered these loads in the single-shot used to be "absolute maximums" and suggested they be cut back for other single-shots.

Dynamit-Nobel published 5,6x61 loading data; for an RWS 4,6g bullet the max was 3,478 fps with R904 for the rimless case. (7th edition, 1995-?). This was reduced to 3,182 fps for the rimmed 5,6x61 vH. R904 is similar to N150, H4350, IMR 4350 and Reloader 17 and 19.

I have just received some Bertram Brass in 5,6x61Rimmed and will be loading them with a view to duplicate the Dynamit Nobel loading of c. 3,100 fps or thereabouts using H4831. If I go any higher, it will be very cautiously! This powder has given me good results in my rimless Mauser action rifle.

JC Munnell wrote: "As is to be expected, for a cartridge with a high powder capacity-to-bore ratio, the slower-burning powders are called for. The various 4831's and 4350's work fine, and I would expect Hodgdon H-1000 and Alliant Rl-25 to be excellent. Even Accurate 8700 was not too slow for this case". His page of loaded data included IMR 4350 which gave 3,723 fps and 3/4" accuracy (at 50 yards ?), with the 5,6x61 rimless. Bullets started blowing up after that, (at 3,774 fps with this load).

Apart from the 2 references cited above, (Rifle's Al Millar and Dynamit-Nobel 1995), that is about all the 5,6x61 Rimmed loading data I have. If anyone has another source, I'd love to hear about it.

Wiederladen by Friehelm Kersting of DEVA did not cover the rimless round in the editions I have. My translation of Friedhelm's warning is; "In this cartridge in particular, a high loading density must be respected". ("Bei dieser Patrone ist ganz besonders auf eine hohe Ladedichte zu achten!")

[mike ford]

Kiwi_bloke,
I have written about my rifle, which is chambered for the rimmed version, in WAIDMANNSHEIL; so I won't retell the whole story here. Suffice it to say, the load by the previous owner; using 4350 @ a little over 3250fps, didn't shoot worth a crap. He was on his death bed, since this was going to be our last project together, I was determined to show him acceptable groups, before the end. I managed to do that by reducing the velocity to right at 3000 fps. with the 22 High Power bullet( the one I had on hand). All the "cautions" about this cartridge pertained to reduced charges of slow burning powder. To reduce the velocity to match the bullet, I didn't want to reduce the charges of slow burning powder, so instead I went to a medium burning powder. The "cautions" didn't address medium burning powders. Since I was able to show my friend decent groups from our last project, I don't regret anything I did to accomplish this. Since that exercise and my friend's passing; a new friend came forward and "bumped up" .224" 80 gr. bullets for me. With those bullets and 7828, I was able to reach 3250+ fps, with decent groups. As a point of interest, factory ammo in my rifle (77gr bullet), only gave a little over 3000fps. My rifle is very precious to me, so I'm not interested in wringing the last fps from it; but I have no argument with anyone else doing that with their own rifle. In fact, it is interesting to see if the new slow powers will finally match the velocities advertised for these cartridges ( the rimmed and rimless versions are two very different cartridges). Just don't loose sight of the fact that the "Secondary Explosion Effect" is not the only source of damaged rifles. In an attempt to find a bullet tough enough to withstand the velocity, one handloader turned solid copper .243" bullets to .228"; the rifle wasn't destroyed, but it was scary. It wasn't a bad idea, but there was no pressure gun to try it in.
Mike

[Diz]

Mike,

Speaking of hard bullets, I just tried to bump a few Swift Sirocco's for a friend and they were the toughest things I tried so far. They were actually springing the top plate on my swaging press and I was having trouble ejecting them. I think they would be an excellent bullet for game with the vH but resizing them it will require extra heavy dies for use in a shop press. I managed to do ten and hope to hear a report on them.

I would caution anyone contemplating using turned solid or these Swift bullets in a vH as Mike mentions because of the extra hardness and the longer bearing surface is sure to create more pressure. It is an interesting cartridge but very high intensity and edgy at best.

Thanks, Diz

[mike ford]

The people that market the solid bullets usually include grooves to reduce pressure. Herter used to sell "wasp waist" bullets, this may reduce pressures also.
Mike

[mike ford]

The people that market the solid bullets usually include grooves to reduce pressure. Herter used to sell "wasp waist" bullets, this may reduce pressures also.
Mike

[Diz]

Mike, you give away our age by remembering those Herter's bullets! Early Nosler bullets were also turned at the partition for the same reason I believe. Interestingly, when I try to bump up partition bullets the area around the partition will not expand due no doubt to the rigidity of the partition and the result looks very much like the old Herter. Thanks for bringing it up. Diz