If i've read your chart correctly your saying 84.0 gr Reloder 15 is an overload as far as pressures are concerned with the Speer 350 grain. As I had no manual with 350 gr. Speer loadings I used my Barnes Manual. My 1992 Barnes reloading manual for a 350 gr copper X bullet starts at 78.0 gr Re 15 at 2498 fps and gives 84.0 grains as Max at 2694 fps. in a 26 inch Test barrel. My chrono states I'm gettin 2500 ish fps with 84.0 grains in a 24 inch brl.
My experience with Barnes X bullets is that I reach max pressures faster with "any caliber X bullet" vs. Speer or Hornady bullets in the same calibers and that any data I've used in my guns developed with the "longer bearing surfaced " X bullets has been less than max in the rifle useing the same powder load with the Speer and Hornadys' . The 84.0 gr. Re 15 load in my Sako is 2 grains under what is my max of 86.0 gr with the 350 Speer, when primers start to change to a flatter shape.
Should have added the usual disclaimer....."These loads were safe in my rifle but need to be worked up to in yours"....Thanx for the reminder.
Yes, the Speer hits max at 84grs. Here is what the 350gr TSX looks like :
Cartridge : .416 Rem. Mag.
Bullet : .416, 350, Barnes 'TSX' 41686
Cartridge O.A.L. L6: 3.600 inch or 91.44 mm
Barrel Length : 24.0 inch or 609.6 mm
Powder : Alliant Reloder-15
Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% 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
-20.0 81 62.40 2120 3492 34192 6305 93.9 1.521
-18.0 83 63.96 2168 3654 36281 6477 94.8 1.484
-16.0 85 65.52 2217 3819 38503 6642 95.6 1.447
-14.0 87 67.08 2265 3986 40866 6800 96.3 1.412
-12.0 89 68.64 2313 4157 43379 6951 97.0 1.377
-10.0 91 70.20 2361 4332 46053 7094 97.6 1.344
-08.0 93 71.76 2409 4508 48897 7228 98.2 1.311
-06.0 95 73.32 2456 4688 51925 7354 98.7 1.279
-04.0 97 74.88 2503 4870 55149 7470 99.1 1.245 ! Near Maximum !
-02.0 99 76.44 2550 5055 58585 7576 99.4 1.212 ! Near Maximum !
+00.0 101 78.00 2597 5243 62248 7671 99.6 1.180 !DANGEROUS LOAD-DO NOT USE!
+02.0 103 79.56 2644 5432 66157 7756 99.8 1.149 !DANGEROUS LOAD-DO NOT USE!
+04.0 105 81.12 2690 5624 70333 7830 100.0 1.119 !DANGEROUS LOAD-DO NOT USE!
+06.0 107 82.68 2736 5818 74799 7892 100.0 1.090 !DANGEROUS LOAD-DO NOT USE!
+08.0 109 84.24 2782 6014 79579 7945 100.0 1.062 !DANGEROUS LOAD-DO NOT USE!
+10.0 111 85.80 2827 6213 84703 7996 100.0 1.035 !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 101 78.00 2692 5630 73589 7354 100.0 1.104 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 101 78.00 2461 4707 51241 7686 95.8 1.280