Does anyone know where I can find Data for 8X68S?

I would like to know what standard pressure is for factory loads. Hintenberger lists 2926fps with a 200gr Nosler Partition. Any Idea what a load of this performance would generate in PSI?

I would also like some case dimensions. I have Clymer's reamer dimensions, but would like case dimensions (rim diameter?)

Load data would be helpful also. I would think that slightly reduced 8mm Rem Mag starting loads would be appropriate as case volumes would be similar (the chamber dimension @ the shoulder is about .223" shorter but is .0108" larger in diameter @ the base, .0085" smaller @ the shoulder. Shoulder angle for the 8X68S is 14 Deg. 33' as opposed to 25 Deg. for the Rem Mag)

An "improved" version with a 40 degree shoulder would be "interesting".

Any links for load data?

[ 08-15-2002, 01:56: Message edited by: wildcat junkie ]

Wildcat

The 3rd edition of the Hornady Handbook of Cartridge Reloading has data for 125 gr, 150 gr, 170 gr and 220 gr bullets. I hope these images are legible.





[ 08-15-2002, 07:35: Message edited by: Mauser98 ]

Case dimensions in inches as listed in the 9th edition of "Cartridges of the World"

Diameters
bullet : .323
base : .522
rim : .510
shoulder : .473
neck : .354

Lengths
case : 2.65
cartridge : 3.38

Unfortunately the rim thickness, neck & body length and shoulder angle aren't part of the data given. As a European cartridge design, the dimensions are controlled by the "Commission Internationale Permanente" (CIP), not by the American standards body SAAMI.

Hello Dan,
Still toying with the 8mm ?? Those M98/Vz500 are perfect for the 7x57. Anyway here's some poop from a Vihtavuori Oy Reloading Guide 5th Ed.for the 8x68S.

Bullet powder/wt. vel. psi/cip
187gr. SP RWS N160 77.9gr. 3070fps 55,114

196gr. SP RWS N160 77.2gr. 3030fps 55,114

200gr. SP Speer N160 72.2gr. 2890fps 55,114

An early 60's Shooters Bible has some ballistic charts with this odd ball since it was chambered for the excellent Mannlicher-Schoenauer.
186gr. H-Mantl 3280vel. 4463ftlbs

8x68S bore dia..310in., groove dia..323in.
chamber throat 1.338in.,.323rear dia., .310in.front dia.,slope ratio 1:100.

H-Mantle bullet length in inches 1.319, wt. 187gr.
Solid Jacket bullet length in inches 1.024, wt. 198gr.

Recommended bbl. twistis 1:28cm(approx. 11inches)


If I come across anything else I'll pass it along.

Bob

manhasset:

How are ya doin? When ya gonna come up and help me get rid of some of these Wild Turkeys and Whitetails that are over-running my place? I planted 61 apple trees this spring. Macintosh, (drop in late September) Cortland (drop in mid October) and Romes. (will drop intermitently in late fall and winter) Got em skattered around in 2 small and 1 large orchard. (Near ladder stands of course) Once these babies start bearing in about 3-4 years, I don't know if I will be able to fend the varmints off!

Cheese and rice manhasset, since we chatted last, I picked up my late father's 30/40 Krag carbine, another cherry matching# M98k with a cut down stock and I just put money down on a M700 Mountain Rifle in .280 Yup a faktury gun!

So many rifles, so little time. (or money)

BTW Midway has Timney "sportsmans on sale for $26.99. I ordered 3 for my VZ500s and the new (to me) M98k. Pretty good price on a pretty good trigger!

From the data you provided, it looks like the 8X68 should be able to churn up 3000fps or so with a 200gr Nosler whilew generating less pressure than a factory 270 load. I am thinking about rechambering my latest M98K to 8X68.

Mauser98:

I could make out the velocities. 2800fps with a 220gr bullet would lead me to believe 3000fps with a 200gr Nosler is realistic.

CMcDermott

The shoulder diameter was particularly helpful as I was concerned obout chamber wall thickness. The chamber walls will only be .008" less than my 8mm-06 Ackley, so I think there would be no problem there. (My smith agrees)

ricciardelli:

I found your data last night, thanks.

Thanks everone for the help.

Well, I've decided to have my cherry M98K rechambered to 8X68S. Very little modification to the action will be needed for this baby. The COL of 3.4" + or - and the taper that is almost identical to 7X57 ought to make this cartridge feed like "greased sausages" in a M98 and there is plenty of chamber wall thickness to handle the 50,000psi to 55,000psi pressure range. (less than a 270 factory load) The chamber wall @ the shoulder will only be .0085" thinner than my 8mm-06 Ackley Improved, and I am loading it to almost 60,000psi. The 23 5/8" barrel will still give me plenty of "poop"! (2900fps = or - with a 200gr Nosler Partition?)

Ought to make a very nice "big stick" rifle for Elk or Moose.

[ 08-19-2002, 00:30: Message edited by: wildcat junkie ]

Wildcat Stay away from slightly reduced loads for the 8mm Rem mag when loading an 8x68. The Rem has a lot more capacity. The Hornady book has loads for their bullets. IMR 4350 and IMR 4831 both work good with 200 gr bullets. The Speer shoots very accurate in my Brno 602 but the Partition is a better big game bullet. Safe start loads in MY RIFLE are about 66grs 4350 with either 200 gr with max about 70-71 grs. Start with 69 grs 4831 and work up to about 76 grs.

I believe the A-Square manual has 8x68 loads, if you can find a copy.