284 Shehane and N560

[kyreloader]

Has anyone used VihtaVouri N560 with either 175g SMKs or 180g Berger VLDs?

I have a good 180g Berger load with H4831SC, but I have alot of N560 and was wondering where to load for similar velocities for practice load.

Thanks.

 

[TonyR]

I did some ladder testing with N560 with the 180 Bergers out of a 31 inch 1:9 Kreiger and overall cartridge length of about 3.2 inches. Maximum velocity was close to 3000 fps but the vertical was not what I wanted. Also, this powder is one of the hottest burning I've tested and I think barrel life would be considerably shorter. So, without the prospects of satisfactory accuracy at a higher velocity, I did not explore it further. It might be worth trying in a shorter barrel to see where it tunes. A ladder test in your own gun is the only way to find out. Start low and work up gradually. I use 0.4 grain steps.

 

[kyreloader]

Can you give me ballpark numbers on the amount of powder you used for your ladder testing?

No real good data out there.

 

[TonyR]

Assuming Lapua 6.5X284 brass necked up to 7mm, CCI BR-2 primers and the bullet seated for a cartridge overall length from the case head to the tip of the bullet of 3.200 inchs, you could start at 54.0 grains of N560 and work up carefully in 0.4 grain steps. It is very important that the chamber be throated to seat the bullet out in the case neck. The pressure goes up very quickly if the bullet is seated farther into the case. 3.2 inches COAL should have the shank/boattail junction of the bullet above the neck/shoulder junction of the case.

 

[kyreloader]

Thanks Tony

 

[RDavies]

I tried it recently in an effort to get up to 2920 fps with my 284. I found the velocity spreads very high. Basicly, some of my rounds were a tad harder to chamber, most likely the ogive being a few though further out into the lands. With N560, the velocity jumped way up 40-50 fps. With H4350 it went up maybe 15 fps. If I left a round in the warm chamber for a while as I was talking or writing notes, the velocity jumped up 50-60 fps. With H4350, it went up about 15 fps.
This was with H4350 velocities of 2800-2820 fps, VS N560 velcities of 2900-2960 fps, so it is comparing apples to oranges, but I will be sticking with the accurate slower load. Trying to get to 2920-2950 fps in my particular barrel with H4831sc just gave me popped primers, but it works in other peoples barrels.