You can use the same loads with the Berger 90 as with the Berger 105. Here are some loads and how they chronographed in an upper I have:
28.5 gr N540 with CCI BR4 primer and Berger 105 VLD .010" in lands, 2706 fps mean velocity, 18 Extreme Spread and 8 fps Std Deviation
29.0 gr N540 with CCI BR4 primer and Berger 105 VLD .010" in lands, 2755 fps mean velocity, 26 Extreme Spread and 9 fps Std Deviation
26.5 gr N135 with CCI BR4 primer and Berger 105 VLD .010" in lands, 2639 fps mean velocity, 15 Extreme Spread and 5 fps Std Deviation
27.0 gr N135 with CCI BR4 primer and Berger 105 VLD .010" in lands, 2682 fps mean velocity, 12 Extreme Spread and 5 fps Std Deviation
27.5 N135 = too hot a load with Berger 105's
28.5 gr RL15 with CCI BR4 primer and Berger 105 VLD .010" in lands, 2710 fps mean velocity, 7 Extreme Spread and 3 fps Std Deviation
29.0 gr RL15 with CCI BR4 primer and Berger 105 VLD .010" in lands, 2772 fps mean velocity, 6 Extreme Spread and 2 fps Std Deviation
29.3 gr RL15 with CCI BR4 primer and Berger 105 VLD .010" in lands, 2798 fps mean velocity, 10 Extreme Spread and 5 fps Std Deviation
28.5 gr Varget with CCI BR4 primer and Berger 105 VLD .010" in lands, 2688 fps mean velocity, 32 Extreme Spread and 16 fps Std Deviation
29.0 gr Varget with CCI BR4 primer and Berger 105 VLD .010" in lands, 2717 fps mean velocity, 19 Extreme Spread and 7 fps Std Deviation
29.3 gr Varget with CCI BR4 primer and Berger 105 VLD .010" in lands, 2743 fps mean velocity, 19 Extreme Spread and 9 fps Std Deviation
I don't have N140 on here but about 28.5 gr of N140,start about .5 gr lower and work up).
Robert Whitley
www.6mmAR.com