Vihtavuori N570 in 7mm Rem Mag

[Deezel]

Well, shot these 2 loads out to 600 yards today and I'm impressed!

Here is the first load tried, 66.9gr. I didn't run them with the chrono because I had a very good idea of velocity. I believe I confirmed this velocity today with my groups. I use Strelok Pro and it gave me my its estimate of 2.5 mils up at 2920 fps. This proved to be bang on.
I knew I pulled my first shot as soon as I pulled the trigger but will leave it in the group picture. If I just used the last 4 shots, the group is 3.38" and an impressive 0.54 moa.

Here's the second group with the 69.1gr charge. The velocity of this one is 3050fps. Strelok suggested 2.3 mils and it too hit pretty much bang on. I'm going to play a bit with seating depth on this load to see if I can tighten up the group some. I'm really hoping I can because I really like the velocity this charge is giving. If I can't get it to tighten up, I'll just use the 66.9gr charge.
Still, this is pretty good accuracy for a hunting rifle.

 

[ppoole]

What brass and seating depth were you using for that.

 

[Deezel]

What brass and seating depth were you using for that.

Winchester brass fired in this chamber
FL resize with shoulder bumped 0.0015"
Trimmed to 2.490"
Necks turned to 0.012"
Bullets seated 0.020" off
Fed 215M primers

This was for all my testing of this powder.

 

[Deezel]

Did some seat testing on the 69.1gr load. Results were what I hoped it would be.

Loaded 6 rounds each with bullet seated 0.130", 0.090", 0.050" off and 6 more that were just touching lands.
I got what I feel is a typical result with this bullet. The farther away it got from the lands, the bigger the group got.
The loads touching the lands held a group of 0.36" and the group at 0.050" off had opened up to 0.968". Noticeable pressure spike (harder rifle kick) with the 0.090" jump and did get a faint ejector wipe with one of the rounds with the 0.130" jump. Neither of these 2 loads grouped well. Both were well over 1". These groups were shot at 100 yards.

Fired the last 3 rounds that were loaded touching the lands at 600 yards. First 2 shots stacked then last one drifted up and left a wee bit. I think the pressure got to me......

Here's a pic of the rifle at my range. The little black box on the back side of the rifle is a battery operated air mattress pump. If you look you can see the hose running into the chamber. This works amazingly well for cooling the barrel between shots.

I'm pretty sure I'm finished with this load development. I'll most likely continue shooting the 69.1gr load and seat the bullets 0.005" off the lands. I will have to try the 66.9gr load with bullets seated 0.005" off just to see how it shoots. Who knows, it may perform better.
All in all, I'm pretty happy with how this has turned out. I'm also very impressed with the speed I'm getting with this powder. I honestly thought I'd end up somewhere around 2975fps, not 3050fps.

 

[ppoole]

Mine likes it at 3063 so that's about where the next node is I believe. I'm glad to see someone else has had good results with this powder.

 

[COmtnman1]

does anyone know where i can get some Viht N570

 

[Deezel]

does anyone know where i can get some Viht N570

If you live in Canada, yes.

 

[COmtnman1]

If you live in Canada, yes.

no, i'm in the USA

 

[DartonJager]

does anyone know where i can get some Viht N570

PRECISELY why I never was willing to risk developing and loads using VV powders. Ten years ago I could get VV OTC at 4 or five stores near me with regularity. Then about 5-6 years ago that dropped to 3 then 4 years ago it dropped to two now only one store near me is the only one that has VV in stock and it's a quite limited selection. I know it's often available mail order but hazmat fees make it for me cost prohibitive.