Hi Erik,
Thank you very much for testing my 7mm Mag loads in QuickLoad!
Would you be kind enough to check the loads I have written below in QuickLoad as well?
7X64: 54-57 grains N560, COL = 3.32"
8X68s: 74-77 grains N560, COL = 3.36"
300 Wby: 79-82 grain N560, COL = 3.56"
For 7mm Mag, I have tested up to 62 grains of N560 (COL= 3.24", 25" barrel). The VihtaVuori manual (2017) shows 60.2 grain of N560 as max for this bullet. I didn't notice any pressure signs and the accuracy was excellent. The same manual also shows larges charges (e.g. 68 grain N560 for a 160 grain Speer bullet). What's your suggestion based on your quick-load analysis? Should I go one or two grain higher (upto 64 grain) or stop?
Thank you,
-Omid
PS. I have a feeling that some loads I'd tested previously were near or exceeding maximum pressure. For example, I think the 300 Wby loads with Norma MRP were too hot. Similarly, some 7mm Mags loaded with Norma 217 were probably at or over max too.
Regarding the 7 Rem mag....with the COAL and barrel length adjusted the Quickload predicted pressure and velocity for 62 grains of 560 are 47974 psi and 2884 FPS, 64 is 52817 PSI and 2977 FPS and 66 grains is 58113 PSI and 3071 FPS. 66.5 Grains 59516 PSI and 3094 FPS.. I'll let you decide what you are comfortable with given what the book max is.
Cartridge : 7 x 64 Brenneke
Bullet : .284, 155, Lapua Naturalis N564 7027
Useable Case Capaci: 60.162 grain H2O = 3.906 cm³
Cartridge O.A.L. L6: 3.320 inch = 84.33 mm
Barrel Length : 25.0 inch = 635.0 mm
Powder : Vihtavuori N560
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 76 43.20 2171 1622 24813 7841 80.7 1.727
-18.0 78 44.28 2224 1703 26279 8142 82.2 1.687
-16.0 80 45.36 2279 1787 27835 8441 83.6 1.647
-14.0 82 46.44 2334 1875 29491 8738 85.0 1.608
-12.0 84 47.52 2389 1965 31251 9030 86.4 1.570
-10.0 86 48.60 2445 2058 33126 9318 87.7 1.533
-08.0 88 49.68 2502 2154 35123 9601 88.9 1.497
-06.0 90 50.76 2558 2252 37251 9876 90.1 1.461
-04.0 91 51.84 2615 2354 39517 10144 91.3 1.426
-02.0 93 52.92 2672 2458 41939 10403 92.4 1.392
+00.0 95 54.00 2730 2565 44524 10652 93.4 1.359
+02.0 97 55.08 2787 2674 47270 10890 94.4 1.326
+04.0 99 56.16 2845 2786 50237 11117 95.3 1.291
+06.0 101 57.24 2903 2901 53395 11330 96.1 1.255 ! Near Maximum !
+08.0 103 58.32 2961 3018 56787 11529 96.8 1.220 ! Near Maximum !
+10.0 105 59.40 3019 3138 60420 11713 97.5 1.186 !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 95 54.00 2898 2890 54066 10908 98.6 1.256 ! Near Maximum !
Data for burning rate decreased by 10% relative to nominal value:
-Ba 95 54.00 2522 2189 36358 9832 84.2 1.471
Cartridge : 8 x 68 S
Bullet : .323, 180, Lapua Naturalis N559 8009
Useable Case Capaci: 74.387 grain H2O = 4.830 cm³
Cartridge O.A.L. L6: 3.336 inch = 84.73 mm
Barrel Length : 25.0 inch = 635.0 mm
Powder : Vihtavuori N560
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 84 59.20 2371 2247 28297 8220 80.9 1.555
-18.0 87 60.68 2433 2367 30137 8537 82.4 1.516
-16.0 89 62.16 2496 2490 32108 8851 84.0 1.477
-14.0 91 63.64 2560 2618 34222 9160 85.5 1.439
-12.0 93 65.12 2624 2751 36491 9463 86.9 1.402
-10.0 95 66.60 2688 2889 38930 9759 88.3 1.365
-08.0 97 68.08 2754 3031 41553 10046 89.7 1.329
-06.0 99 69.56 2819 3177 44375 10324 90.9 1.294
-04.0 101 71.04 2886 3328 47419 10590 92.1 1.259
-02.0 104 72.52 2952 3484 50701 10843 93.3 1.223
+00.0 106 74.00 3019 3644 54250 11082 94.3 1.185 ! Near Maximum !
+02.0 108 75.48 3087 3808 58091 11306 95.3 1.149 ! Near Maximum !
+04.0 110 76.96 3154 3977 62252 11513 96.2 1.113 ! Near Maximum !
+06.0 112 78.44 3222 4150 66772 11701 97.0 1.079 !DANGEROUS LOAD-DO NOT USE!
+08.0 114 79.92 3290 4327 71692 11870 97.7 1.045 !DANGEROUS LOAD-DO NOT USE!
+10.0 116 81.40 3359 4508 77052 12017 98.4 1.013 !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 106 74.00 3202 4097 66142 11242 99.1 1.089 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 106 74.00 2789 3110 44076 10306 85.4 1.297
Cartridge : .300 Weath. Mag.
Bullet : .308, 170, Lapua Naturalis LR N558 7105
Useable Case Capaci: 88.121 grain H2O = 5.722 cm³
Cartridge O.A.L. L6: 3.560 inch = 90.42 mm
Barrel Length : 25.0 inch = 635.0 mm
Powder : Vihtavuori N560
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 76 63.20 2467 2298 29177 10075 86.0 1.584
-18.0 78 64.78 2529 2414 31005 10433 87.5 1.547
-16.0 80 66.36 2591 2533 32953 10785 88.8 1.510
-14.0 82 67.94 2653 2657 35030 11129 90.1 1.474
-12.0 84 69.52 2715 2783 37245 11464 91.4 1.438
-10.0 86 71.10 2778 2913 39607 11789 92.5 1.404
-08.0 88 72.68 2841 3047 42117 12102 93.6 1.370
-06.0 89 74.26 2904 3184 44822 12402 94.6 1.336
-04.0 91 75.84 2967 3324 47700 12687 95.6 1.304
-02.0 93 77.42 3031 3467 50775 12956 96.4 1.267
+00.0 95 79.00 3094 3613 54061 13208 97.2 1.231
+02.0 97 80.58 3157 3762 57538 13441 97.9 1.196 ! Near Maximum !
+04.0 99 82.16 3220 3914 61231 13655 98.5 1.162 ! Near Maximum !
+06.0 101 83.74 3283 4068 65174 13847 99.0 1.129 !DANGEROUS LOAD-DO NOT USE!
+08.0 103 85.32 3346 4225 69386 14017 99.4 1.097 !DANGEROUS LOAD-DO NOT USE!
+10.0 105 86.90 3408 4384 73890 14164 99.7 1.066 !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 95 79.00 3258 4007 65115 13121 100.0 1.135 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 95 79.00 2879 3129 43643 12556 89.9 1.343