338 Lapua and N570

[Larry87]

Hello all, I recently did some testing with N570 in my Savage 110BA 338 Lapua. First things first I used Lapua Brass FL sized, Winchester LRM primer (the only ones I could find), and 250gr SMKs. I got the base line data from Vihtavuori's load center. This testing was for speed and not for accuracy I was going for the 3000fps with the 250. I started with 88gr and worked my way up to 96.5gr going up a grain at a time except for the last one. There were no signs of over pressure even in the extreme heat, testing day was in 100°+ here in the Arizona desert. The data is as follows:
88gr - 2650
89gr - 2699
90gr - 2754
91gr - 2777
92gr - 2795
93gr -2836
94gr did not record data.
95gr -2842
96gr - 2917
96.5gr - 2956

I was getting a consistent 50ish FPS increase with every 1 gr except 93 to 95 which should have been about 100fps but only increased by 6. I think it was a mistake on my part with the scale. I am going to test 97gr and 97.5 to see what the results are as far as speed to see if I get pressure. Then once I get to the 3000fps I am going to test for accuracy.

 

[Archery1973]

I want to follow your test with N570.

 

[Archery1973]

Any news? Anybody else running N570 with .338 Lapua?

 

[idaho elk hunter]

You have ran to the point of no return. Hence the minimal velocity gain after adding more powder. H1000 can not be beat for this cartridge. If you want to save money then get some SMK 338 bullets, H1000, WIN Mag primers and work up. This will ALWAYS give the best groups in the Savage. (Make sure barrel is clean) You can play with seating depth once you establish your sweet spot. Typically work at max COAL. And get to max pressures and back off 2 gr powder. If you really want to hit the power in the 338 take it to a smith and make it a 338-378 Weatherby..A easy 150 to 200 fps more, rl 25 will put a 250 gr pill to 3250

 

[Larry87]

Well I have been really busy with starting a new job and moving but I was able to get some 97gr pushing the 250SMK down the tube and the results are impressive. Now there was a difference between altitude and temp compared to the first testing I did. Test at 8960 ft above sea level and temp was around 30-35* F. I had more rounds but only chrono'd two.
2996fps
3037fps

Side note I loaded up 3 91.5gr and 2 92gr H1000 behind the Berger 300gr pill. Same temp and altitude as above.
91.5gr
2737fps
2737fps
2721fps

92gr
2772fps
2789fps.