doublegunshop.com - home Forums General Discussion German & Austrian Sporting Guns @ doublegunshop.com August Jung Viernau-5.6x61R vom Hofe Super Express

Um, I have migrated on to VV N 165 in my 5,6X61R trek and have worked up from 41.5 grains to 45 grains of VV N 165 which nets an average velocity of right @ 3100 ft/s. You can run all these programs in the fantasy / pushbutton world, which does indeed make it a bit simplier, but empirical data is where I have firm footing....

Once you break the 3000 ft/s threshold, with whatever propellant you chose, this cartridge just seem to perform the same: hitting in the same spot, albeit w/ iron sights.


]

Above is a Date Syrup Can that I use specifically for the final shot of a series. Now all these holes are from the same bullet weight but different propellants & different loads. On my last shot w/ 45 grains of VV N 165 I hit in the same hole as a previous load(I have a foto of the reverse side if there are any Doubting Thomas' out there......). I have shot the cartridge enough that when you break the 3000 ft/s - 3100 ft/s threshold, I can just tell by the recoil where we are. Can the new fangled bullet/powder program discern that?

I think by the time I approach 3200 ft/s - 3300 ft/s, VV N 165 is going to nicely fill the case. This maybe a necessity and possibly warrant a Magnum Primer, but I haven't gotten to that point just yet. My hopes are to see similar success w/ VV N 170. But to press the envelope forward this, I will need Glass atop the gun & they will take some time.


Hochachtungsvoll,,


Raimey
rse

As a sidenote, most of the time, the 79/80 grain bullet passes thru the Date Syrup Can & it never stirs.... Pretty much the same w/ the smaller evaporated milk can.


Hochachtungsvoll,,


Raimey
rse

I believe I have come to the terminal segment w/ VV N 165 using 3 grams on the nose for the 5,6X61R vom Hofe Super Express @ 3270 ft/s, with the standard deviation being surprisingly small for a handful of shots w/ a 79/80 grain Northern Precision Bonded Hollow Point. The powder fills the case nicely and keeps the velocity variation low, which seems to be a necessity for this cartridge. In the near future I will give VV N 170 a try....


Hochachtungsvoll,,


Raimey
rse

Raimey,
One thing empirical data does not give you until too late is a good estimate of chamber pressure. The "stringing" of the shots on the syrup can is typical of "stringing" caused by the rifle barrel heating up while the shot barrel does not. If you are shooting for a group, you only need to wait longer between shots. If you are hunting, the animal will be dead or gone before the barrel heats up anyway, so it won't be a problem.
Mike

So Ford are you saying the program can measure my chamber pressure?? How does it measure my chamber volume? Pretty neat device for remote sensing??? That >>Stringing<< is me pulling to the left trying not to shoot the Sun-Shade off the Chrony. There are days if not weeks between all those shots. I wait between shots to let the barrel cool.

Hochachtungsvoll,

Raimey
rse

No. It is a (very good) program, and a program measures not.

It extrapolates. Rather good and rather reliably.

Raimey,
The program will take the data you input, including either actual case capacity or recorded capacity of standard case, bullet specs. barrel length, Pressure limitations, etc. and give you estimated velocity and charge weight of a specific powder or powders or all available powders. Or, if you input the specs and proposed charge weight of a specific powder, it will estimate the highest pressure and velocity.
Mike

Oh, so it is an estimation or assumption, if you will. Remember, Assumption is the Antithesis of Exactitude.....


Hochachtungsvoll,,


Raimey
rse

So Ford what pressure did you get your chamber up to & what ballistics program did you use?


Hochachtungsvoll,,


Raimey
rse

Raimey,
That was 20+ years ago and I didn't have access to a ballistics program. I had to trust predecessor's advice and guidance as well as the chronograph and targets.
It is neither an estimation nor assumption, it is a calculation based the results of many previous scientific studies/tests.
Mike