Hello

I'm working with Sierra 160gr Spitzer BTs and Privi brass. Fireformed, the brass holds 64grs of water filled to the top.
I'm curious what Quickload might have to say about pressures.
In particular, I'm curious about two newer powders,
HUNTER
4000-MR

Thanks much

Here's what QL predicts with Hunter.
I've adjusted to case capacity for 64gr.
Quickload recommends a max pressure of 51k PSI.
You will have to decide what is right for your rifle.

Cartridge          : 7 x 57 mm Ack. Imp.
Bullet             : .284, 160, Sierra SPBT 1920
Useable Case Capaci: 57.552 grain H2O = 3.737 cm³
Cartridge O.A.L. L6: 3.071 inch = 78.00 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Ramshot Hunter

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.971% 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

-09.7   85    46.50   2492    2205   38821   9483     96.6    1.453
-08.7   86    47.00   2517    2251   40005   9585     96.9    1.433
-07.8   87    47.50   2543    2298   41223   9685     97.3    1.413
-06.8   88    48.00   2569    2344   42479   9781     97.6    1.393
-05.8   89    48.50   2595    2392   43765   9874     97.9    1.374  ! Near Maximum !
-04.9   89    49.00   2620    2439   45109   9964     98.2    1.356  ! Near Maximum !
-03.9   90    49.50   2646    2487   46487  10051     98.5    1.337  ! Near Maximum !
-02.9   91    50.00   2671    2535   47903  10135     98.7    1.319  ! Near Maximum !
-01.9   92    50.50   2697    2584   49355  10215     98.9    1.301  ! Near Maximum !
-01.0   93    51.00   2722    2633   50846  10292     99.1    1.283  !DANGEROUS LOAD-DO NOT USE!
+00.0   94    51.50   2748    2682   52379  10365     99.3    1.266  !DANGEROUS LOAD-DO NOT USE!
+01.0   95    52.00   2773    2731   53958  10434     99.5    1.249  !DANGEROUS LOAD-DO NOT USE!
+01.9   96    52.50   2798    2781   55586  10499     99.6    1.233  !DANGEROUS LOAD-DO NOT USE!
+02.9   97    53.00   2823    2831   57263  10561     99.7    1.216  !DANGEROUS LOAD-DO NOT USE!
+03.9   98    53.50   2848    2882   58991  10619     99.8    1.200  !DANGEROUS LOAD-DO NOT USE!
+04.9   99    54.00   2873    2933   60772  10673     99.9    1.184  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 3% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 3% relative to nominal value:
+Ba     94    51.50   2788    2761   55468  10300     99.9    1.236  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 3% relative to nominal value:
-Ba     94    51.50   2703    2595   49280  10376     98.3    1.299  ! Near Maximum !
  

Thanks so much

I did a ladder last weekend with 51.0grs the last interval. 50.0grs was the most accurate group, with 50.5 in second. 51.0 the group was not good.



So this is pretty much right on the money..
Very nice..

QL assumes 70 degrees, so at 45-50 degrees, you are about where I would expect. Thanks for the update, it's always nice to see how accurate the QL predictions actually are.

1 1/8" at 200 yards is a good group. I'd say you are on your way to a real shooter.

NP.. Going to be working with a .300 H&H in the near future. Maybe I'll hit you up again.
Thanks