QL 257 Weatherby

[frankm]

I shoot 66-66.5 grs of R22 in my 257 Weatherby and after experimenting with R26 in some other calibers wondering what it's like look in 257 WB.

Would someone mind running a QL on R22 and R26 as a comparison and place to start loading. Here's the specifics:

257 Weatherby
Weatherby brass
F215
115 Nosler BT
3.420 OAL. ( lots of freebore! )
26" barrel

Thanks to whoever gets to it. Appreciate it.
Frank

 

[Dwh7271]

Cartridge          : .257 Weath. Mag
Bullet             : .257, 115, Nosler BalTip 25115
Useable Case Capaci: 79.753 grain H2O = 5.178 cm³
Cartridge O.A.L. L6: 3.420 inch = 86.87 mm
Barrel Length      : 26.0 inch = 660.4 mm
Powder             : Alliant Reloder-26 *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   68    53.74   2698    1859   30465  12065     98.2    1.681
-18.0   70    55.09   2764    1951   32596  12348     98.9    1.641
-16.0   71    56.43   2829    2044   34837  12602     99.4    1.601
-14.0   73    57.77   2894    2139   37212  12824     99.8    1.562
-12.0   75    59.12   2958    2234   39730  13013    100.0    1.514
-10.0   77    60.46   3021    2331   42398  13172    100.0    1.468
-08.0   78    61.81   3083    2428   45226  13323    100.0    1.423
-06.0   80    63.15   3145    2525   48221  13470    100.0    1.381
-04.0   82    64.49   3205    2623   51393  13615    100.0    1.340
-02.0   83    65.84   3265    2722   54754  13756    100.0    1.301  ! Near Maximum !
+00.0   85    67.18   3324    2821   58315  13894    100.0    1.264  ! Near Maximum !
+02.0   87    68.52   3382    2921   62089  14028    100.0    1.227  ! Near Maximum !
+04.0   88    69.87   3440    3021   66088  14159    100.0    1.193  !DANGEROUS LOAD-DO NOT USE!
+06.0   90    71.21   3497    3123   70330  14286    100.0    1.160  !DANGEROUS LOAD-DO NOT USE!
+08.0   92    72.55   3554    3225   74829  14409    100.0    1.128  !DANGEROUS LOAD-DO NOT USE!
+10.0   94    73.90   3610    3328   79605  14529    100.0    1.097  !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     85    67.18   3445    3031   70589  13470    100.0    1.162  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba     85    67.18   3138    2515   45989  14473     99.8    1.403

 

[frankm]

Thx. Looks like a guy could get real close to 3400 fps with careful load workup. I seen where a couple guys on LRH said it's a little quick for maximum fill in 257 WB case. Maybe something closer to R33 or Retumbo or the new 8133 would offer better case fill and possibly an extra 50 fps or so.