Home Forums Reloading Reloading Software Would someone run a 257 Roberts load.

Cart: .257
Bullet: 110 Accubond
Bullet Len: 1.195
Boattail Diam: .220
Powder: IMR4350
Charge: 47.0 gr.
Case Len: 2.230
H2O cap: 59gr.
COAL: 2.873
Bullet Jammed/: No .045 off
Barrel len.: 20"
Twist: 1:10

Chronoed @ 2965 fps average from my rifle.

I did some Powley Computer pressure #s and came up with:
CUP.....47700
PSI.....56000

Just wondering how close they are to QuickLoad.

Thanks.

Ed,
First of all I recently acquired QLoad and am not comfortable with its use yet. Also, please be advised - treat the data as a guide and work up loads. (use at your own risk) this information is strictly theoretical. Now I feel better about posting the following. Predicted velocity is 2,938fps @ 59,526 PSI

Cartridge : .257 Roberts
Bullet : .257, 110, Nosler AccuBond 53742
Useable Case Capaci: 51.949 grain H2O = 3.373 cm�
Cartridge O.A.L. L6: 2.873 inch = 72.97 mm
Barrel Length : 20.0 inch = 508.0 mm
Powder : IMR 4350

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 79 37.60 2356 1356 32062 10171 87.4 1.340
-18.0 81 38.54 2414 1423 34155 10514 88.7 1.308
-16.0 83 39.48 2472 1493 36373 10850 89.9 1.275
-14.0 85 40.42 2530 1564 38706 11179 91.1 1.240
-12.0 87 41.36 2588 1636 41168 11500 92.2 1.203
-10.0 89 42.30 2647 1711 43784 11810 93.2 1.167 ! Near Maximum !
-08.0 91 43.24 2705 1787 46561 12110 94.2 1.133 ! Near Maximum !
-06.0 93 44.18 2763 1865 49511 12397 95.1 1.101 ! Near Maximum !
-04.0 95 45.12 2822 1945 52646 12672 95.9 1.069 !DANGEROUS LOAD-DO NOT USE!
-02.0 97 46.06 2880 2026 55980 12932 96.7 1.039 !DANGEROUS LOAD-DO NOT USE!
+00.0 99 47.00 2938 2108 59526 13177 97.4 1.010 !DANGEROUS LOAD-DO NOT USE!
+02.0 101 47.94 2996 2193 63300 13405 98.0 0.981 !DANGEROUS LOAD-DO NOT USE!
+04.0 103 48.88 3054 2279 67321 13616 98.5 0.954 !DANGEROUS LOAD-DO NOT USE!
+06.0 105 49.82 3112 2366 71607 13808 99.0 0.927 !DANGEROUS LOAD-DO NOT USE!
+08.0 107 50.76 3170 2454 76181 13980 99.4 0.902 !DANGEROUS LOAD-DO NOT USE!
+10.0 109 51.70 3227 2544 81067 14132 99.6 0.877 !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 99 47.00 3072 2306 69837 13115 99.9 0.939 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 99 47.00 2763 1864 49395 12646 91.2 1.100 ! Near Maximum !

In a modern rifle is 59k psi really dangerous? Many modern cartridges use much higher limits. Where is the threshold for +P+?