Quickload pressure for 303 Brit?

08 March 2018, 00:47

Could a quickload user help me with a 303 Brit load? I am loading low pressure loads for an old cape gun and would like to know ballpark I'm in. Specs:
303 British
174 Gr Bullet
36 grains RL15
Remington cases

08 March 2018, 04:32

ramrod340

  Cartridge          : .303 British (SAAMI)
Bullet             : .312, 174, Hornady RN 3130
Useable Case Capaci: 50.651 grain H2O = 3.289 cm³
Cartridge O.A.L. L6: 3.075 inch = 78.11 mm
Barrel Length      : 24.0 inch = 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   62    28.80   1742    1172   17099   4567     79.2    1.968
-18.0   63    29.52   1782    1227   17984   4735     80.4    1.926
-16.0   65    30.24   1822    1283   18915   4902     81.6    1.885
-14.0   66    30.96   1863    1341   19893   5070     82.8    1.845
-12.0   68    31.68   1903    1399   20921   5236     83.9    1.806
-10.0   69    32.40   1944    1460   22002   5401     85.0    1.768
-08.0   71    33.12   1984    1521   23139   5565     86.1    1.731
-06.0   72    33.84   2025    1584   24333   5728     87.2    1.695
-04.0   74    34.56   2066    1648   25587   5888     88.2    1.660
-02.0   76    35.28   2106    1714   26893   6046     89.2    1.626
+00.0   77    36.00   2147    1781   28249   6202     90.1    1.592
+02.0   79    36.72   2187    1849   29660   6355     91.0    1.560
+04.0   80    37.44   2228    1918   31133   6505     91.9    1.528
+06.0   82    38.16   2269    1989   32678   6651     92.7    1.496
+08.0   83    38.88   2309    2060   34298   6793     93.5    1.466
+10.0   85    39.60   2350    2133   35997   6932     94.2    1.436

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     77    36.00   2277    2003   33564   6464     96.3    1.488
Data for burning rate decreased by 10% relative to nominal value:
-Ba     77    36.00   1991    1532   23093   5692     81.0    1.717

08 March 2018, 19:26

bobc

Thanks, went back to check and had asked same question a few years ago and you helped then! Question: since 36 gr is chrono at 1950 fps, it is reasonable to assume that pressure is more like the 30 grain load at that same speed?

08 March 2018, 19:42

ramrod340

First I would adjust the barrel length to match yours as well as the exact 174gr bullet. Add the fired case water capacity and rerun. All that said if after adjustments everything stayed the same I would feel pressure was more like the 32.4 load not the 36.