Anyone who knows what the normal twist rate would be for these two calibers?

5,6x57R 6,5x68R

5,6x57R:

Drall-Länge is 250mm (roughly 1 turn in 10 inches).

6,5x68R:

Drall-Länge is the same at 250mm.

Both of these were set by CIP June 14, 1984.

In "Handbuch fur den Wiederlader" they say it's 250mm for the 5.7x57R but 280 mm for 6.5x68R

250mm or 280mm. !!!! Mind blowing really!! Then minimum twist charts tell me that the maximum weight for the 6,5 or .264 bullet would be 120 or a 130 grains. I know this caliber is made for speed, but that is ridiculous. A 6,5x55Sweede, with much less room for powder, easily carries a 150grain bullet and most shoot a 160gr. well. I don't doubt what you tell me, but I just hope the second hand and very beautyfull Ferlach gun, I am looking at buying, has a better twist for heavier bullets. Otherwise I have no use for it. A twist like that will minimize the bullet choises to an extreme degree.

Any one who knows what the 6,5x65R twist is? Not the same I hope...

Thanks guys

A twist rate of 1:250mm will stabilize 140 grain bullets. The 125 grain Nosler Partition will do the job just fine.

I will post the twist rate for the 6,5x65R tomorow. My Patrone und Lagermasse CD is at the clinic/office. My copy of Weiderladen is in the mail from Germany to the US as I type this (I hope, anyway).

The 6,5x55SE has the steep twist rate because it was designed for the 160 grain bullets at slow speeds.

quote:

Originally posted by lawndart:
The 6,5x55SE has the steep twist rate because it was designed for the 160 grain bullets at slow speeds.

Yes I know that, but why not make the 6,5x68R as steep as the 6,5x55...?? 6,5x55 does not overstabilize lighter bullets, so I see no reason why 6,5x68R should be limited to 140gr. bullets max, by its twist rate. Am I not seeing something here??

The primary reason for the 6.5x68 is long range flat shooting with bullets up to 127gr (RWS load)

Lesser powered 6.5 rounds manage to shoot light bullets in tight twists with no problems. A 6.5x68 can manage 3,600fps with a 100gr bullet which might be stressed enough with an 8twist to fly apart.....

quote:

Originally posted by 1894mk2:
The primary reason for the 6.5x68 is long range flat shooting with bullets up to 127gr (RWS load)

Lesser powered 6.5 rounds manage to shoot light bullets in tight twists with no problems. A 6.5x68 can manage 3,600fps with a 100gr bullet which might be stressed enough with an 8twist to fly apart.....

Of course... I did'nt think of that. The bullet being overstressed is a problem at high speeds. But there we go again speed for flat trajectory.. I just checked my software to compare trajectory of a 140gr. 6,5 to a 100gr ditto, going very fast 3600 (is very fast to me)
There is almost no difference @400m. (20cm.) less @300 and and ridiculously little @200m. which brings me to think that now as allways, accuracy of the load is much more important. Especially in our world of today, where we have rangefinders to help with the long range shots.
I like the gun a lot for it's beauty, but the caliber is crappy and limited. I see that now

Thanks for your help guys

Niels

Any idea how long a barrel lasts in a caliber like 6,5x68R and 5,6x57R? I mean that much powder must burn some throat right. How many shots do you think it has in it?
The gun is from 1965...

Niels

[QUOTE]I will post the twist rate for the 6,5x65R tomorow. My Patrone und Lagermasse CD is at the clinic/office. My copy of Weiderladen is in the mail from Germany to the US as I type this (I hope, anyway).QUOTE]

Hi Lawndart

Did you post the twist rate for 6,5x65R

Best regards
Niels

Where do I buy "Handbuch fur den Wiederlader" ?

I think I bought mine over 20 years ago from a Kettner store. The book is written by K.D. Meyer and edited in Germany. I don't know if it's still on sale.