fwiw in my 30-06 the 150 e tip did about 60 fps faster than cup and core bullets with the same load. Here is a quickload projection. My version doesn't have the etip so I used the older (longer) barnes xbt as a "like" bullet. If this data is usable and I think it is you are near max based on speed.

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Cartridge          : .308 Win.
Bullet             : .308, 150, Barnes 'X' BT 30817
Cartridge O.A.L. L6: 2.800 inch or 71.12 mm
Barrel Length      : 21.5 inch or 546.1 mm
Powder             : Hodgdon VARGET

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step    Fill. Charge   Vel.  Energy   Pmax   Pmuz  Prop.Burnt B_Time
 %       %    Grains   fps   ft.lbs    psi    psi      %        ms

-10.0   95    40.95   2549    2164   48258   7542     94.1    1.105
-09.0   96    41.41   2575    2209   49609   7630     94.5    1.093
-08.0   97    41.86   2601    2253   50999   7716     94.8    1.081
-07.0   98    42.32   2627    2298   52430   7800     95.2    1.069  ! Near Maximum !
-06.0   99    42.77   2653    2344   53903   7883     95.6    1.057  ! Near Maximum !
-05.0  100    43.23   2679    2390   55420   7964     95.9    1.045  ! Near Maximum !
-04.0  101    43.68   2705    2437   56983   8043     96.3    1.033  ! Near Maximum !
-03.0  102    44.14   2731    2484   58593   8120     96.6    1.022  ! Near Maximum !
-02.0  103    44.59   2757    2532   60253   8195     96.9    1.010  !DANGEROUS LOAD-DO NOT USE!
-01.0  104    45.05   2783    2580   61963   8268     97.2    0.999  !DANGEROUS LOAD-DO NOT USE!
+00.0  105    45.50   2809    2628   63729   8340     97.5    0.988  !DANGEROUS LOAD-DO NOT USE!
+01.0  107    45.96   2835    2677   65557   8408     97.7    0.976  !DANGEROUS LOAD-DO NOT USE!
+02.0  108    46.41   2861    2727   67450   8475     98.0    0.965  !DANGEROUS LOAD-DO NOT USE!
+03.0  109    46.87   2887    2777   69410   8539     98.2    0.954  !DANGEROUS LOAD-DO NOT USE!
+04.0  110    47.32   2913    2827   71441   8601     98.5    0.944  !DANGEROUS LOAD-DO NOT USE!
+05.0  111    47.78   2939    2878   73545   8660     98.7    0.933  !DANGEROUS LOAD-DO NOT USE!

Results caused by � 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba    105    45.50   2927    2854   73438   8271     99.9    0.937  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba    105    45.50   2656    2350   53915   8059     91.7    1.050  ! Near Maximum !