264 win mag reloading - n570 powder

[cb4128]

Wanting to try this Vihtavouri N570 that I finally got my hands on.

Have a custom throated 264 win mag for 140gr bergers and have used retumbo with pretty good results so far.

Does anyone have any experience with this combo? Or, any advice on where to start based on 26 nosler load data?

Thanks!

 

[B23]

Surprisingly, QL estimates N570 as only being about 50fps faster than Retumbo.

QL shows a max load of Retumbo with the 140 Berger from a 26in barrel being 3200fps and a max load of N570 at 3250fps. Your real world results may vary from that though.

 

[cb4128]

Ok, thanks for the help. Any idea on minimum and max load?

Had a decent load with the Retumbo but the ES and SD's weren't where I wanted them - accuracy was 3/8" though pretty consistently

 

[cb4128]

bumping this back up - about to get the 156gr bergers in hand to try out!

Any help with this powder, retumbo or rl 26 would be a big help!

Thanks

 

[Rhett Crider]

cb, I've got the 156s on the way too. Had to dope QL bullet file but N570 looks real good w/ the 156. At 3.340 and pushing max pressure it's calculating 3100MV on 26" barrel. Max being 70G at the 1.330ms node. Back it down to 63G and work up is what I'll be doing. Mine loves Retumbo for the 140 class bullets.

 

[cb4128]

Ok awesome! Thanks for the input. My 264 has a custom reamer and at 20 thousands off the COAL is 3.435".

I'll likely start off around the same powder charge as you though.

- what was your load for the retumbo and 140's?

 

[Rhett Crider]

I am ending up at 68.8-70.0G w/ 143ELDx @ 3.340. 68.2G was very accurate but my barrel sped up so I ran it from 67.8 to 70.2 in 0.2 increments. Had 1/4 MOA vertical and 1/2-3/4 Horizontal at 68.8 and 70.0. Need to get back to the range to finish. Too hot right now. Need to chrono also. Previous load was 3040MV

 

[cb4128]

Nice!

 

[Rhett Crider]

Yeah. Really like that rifle. Running a Bartlien 3B in 8 twist on M-70 EW.