I posted my preliminary results in another thread for my 338 NMI and 250gr SDB-2's. I'll post them here also for those interested.
I haven't been able to get out and validate to 1000 and beyond yet due to snowfall amounts here. All the deer and elk are pushed down low and the usual areas that are accessible this time of year for me are not usable due to wildlife.
Results so far are promising and I'll proceed as permitted.
Rifle specs
RBROS Rifles custom build
24 inch Proof Research carbon wrapped 9.4 twist barrel.
Nightforce 5-25 ATACR for the glass
I've only tried 2 powders so far
N570 did not give me the velocity I expected to the amount I used.
Peterson brass annealed in AMP machine. FL size with Whidden custom bushing die. Fed 215 GM primers
Air temp 22*
Results follow
92- 2914,2907
92.5- 2890,2912
93- 2909,2922
93.5- 2924,2914 crunching powder seating the bullet
94- 2933 adjusted seating down .003 to get proper seating. No pressure signs.
Air temp 29*
RL26
89.5- 2968 cold bore, 2948
90- 2983, 2970
90.5- 2994, 2994
91- 3021, 3015
91.5- 3061 bolt click at top
Loaded 4 more with RL26@ 90.5 grains. .030 off the lands
100 yard target
I will wait for weather and wildlife conditions to improve before I proceed further.
I would like to try N565 as it has shown great results in some other cases. I'm am out of that powder and waiting anxiously for it to become available again! I think it will give great results.
I also will try HBN coating on these 250's and document those results as well