Tweet
Hello everyone I wanted to reach out to see if anyone had some advice on loading .223/5.56 62GR FMJBT. I have looked at data from the manufacturer and they recommend starting at 25gr to maximum of 26.8. This seems a bit high so I cross reference it with quickload and it does not recommend exceeding 23GR as you then hit max pressure. I posted the quickload step up below.
Cartridge : .223 Rem. (SAAMI)
Bullet : .224, 62, Hornady FMJBT
Useable Case Capaci: 25.660 grain H2O = 1.666 cm³
Cartridge O.A.L. L6: 2.260 inch = 57.40 mm
Barrel Length : 16.0 inch = 406.4 mm
Powder : Vihtavuori N140 *C
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 17.68 1977 538 20780 6863 78.2 1.238
-18.0 78 18.12 2026 565 22024 7132 79.7 1.209
-16.0 80 18.56 2076 593 23346 7400 81.2 1.180
-14.0 82 19.01 2126 622 24750 7667 82.6 1.151
-12.0 84 19.45 2176 652 26241 7932 84.0 1.124
-10.0 86 19.89 2227 683 27826 8194 85.4 1.096
-08.0 88 20.33 2278 715 29512 8453 86.7 1.070
-06.0 90 20.77 2330 747 31303 8707 87.9 1.043
-04.0 91 21.22 2382 781 33210 8956 89.2 1.018
-02.0 93 21.66 2434 815 35242 9198 90.3 0.992
+00.0 95 22.10 2486 851 37404 9434 91.4 0.967
+02.0 97 22.54 2538 887 39709 9662 92.5 0.940
+04.0 99 22.98 2591 924 42168 9881 93.5 0.914
+06.0 101 23.43 2644 962 44792 10091 94.4 0.889
+08.0 103 23.87 2696 1001 47592 10290 95.3 0.865 ! Near Maximum !
+10.0 105 24.31 2749 1041 50596 10479 96.1 0.841 ! Near Maximum !
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 22.10 2641 960 45117 9806 97.4 0.890
Data for burning rate decreased by 10% relative to nominal value:
-Ba 95 22.10 2299 728 30609 8633 82.1 1.050
Cartridge : .223 Rem. (SAAMI)
Bullet : .224, 62, Hornady FMJBT
Useable Case Capaci: 25.660 grain H2O = 1.666 cm³
Cartridge O.A.L. L6: 2.260 inch = 57.40 mm
Barrel Length : 16.0 inch = 406.4 mm
Powder : Vihtavuori N140 *C
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 17.68 1977 538 20780 6863 78.2 1.238
-18.0 78 18.12 2026 565 22024 7132 79.7 1.209
-16.0 80 18.56 2076 593 23346 7400 81.2 1.180
-14.0 82 19.01 2126 622 24750 7667 82.6 1.151
-12.0 84 19.45 2176 652 26241 7932 84.0 1.124
-10.0 86 19.89 2227 683 27826 8194 85.4 1.096
-08.0 88 20.33 2278 715 29512 8453 86.7 1.070
-06.0 90 20.77 2330 747 31303 8707 87.9 1.043
-04.0 91 21.22 2382 781 33210 8956 89.2 1.018
-02.0 93 21.66 2434 815 35242 9198 90.3 0.992
+00.0 95 22.10 2486 851 37404 9434 91.4 0.967
+02.0 97 22.54 2538 887 39709 9662 92.5 0.940
+04.0 99 22.98 2591 924 42168 9881 93.5 0.914
+06.0 101 23.43 2644 962 44792 10091 94.4 0.889
+08.0 103 23.87 2696 1001 47592 10290 95.3 0.865 ! Near Maximum !
+10.0 105 24.31 2749 1041 50596 10479 96.1 0.841 ! Near Maximum !
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 22.10 2641 960 45117 9806 97.4 0.890
Data for burning rate decreased by 10% relative to nominal value:
-Ba 95 22.10 2299 728 30609 8633 82.1 1.050
Comment