Guide # 6 & .300RUM

[Powerstroke]

Just curious about the load data with the .300RUM and both the 165/168 grain bullets w/Retumbo and then the 180's with Retumbo ?
Generally see the higher charges with the lighter bullets ??
Max charge listed for 165 / 168 is 98.0 Grains

Max charge listed for the 180 grainers is 99.0 grains.

I shot 99.0 grains of Retumbo this weekend with the 180gr B-tip. I had a difficult time extracting the case. Primers appeared ok and no tell-tale visual singns on the case, just difficult extraction.

I was almost thinking there may be an issue with neck sizing these rather than full length, but the other 15 rounds of different combos didn't have the same issue....
Thoughts ?

 

[FOTIS]

Cartridge : .300 Rem Ultra Mag
Bullet : .308, 165, Nosler AccuBond 55602
Cartridge O.A.L. L6: 3.598 inch or 91.39 mm
Barrel Length : 26.0 inch or 660.4 mm
Powder : Hodgdon Retumbo

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 85 80.80 2600 2477 30920 10949 96.1 1.671
-18.0 87 82.82 2670 2613 33222 11243 97.3 1.627
-16.0 90 84.84 2740 2751 35706 11503 98.3 1.583
-14.0 92 86.86 2810 2892 38389 11726 99.1 1.536
-12.0 94 88.88 2879 3036 41289 11908 99.6 1.484
-10.0 96 90.90 2947 3181 44427 12048 99.9 1.435
-08.0 98 92.92 3014 3328 47822 12145 100.0 1.387
-06.0 100 94.94 3080 3475 51504 12227 100.0 1.341
-04.0 102 96.96 3145 3624 55497 12306 100.0 1.297 ! Near Maximum !
-02.0 104 98.98 3209 3773 59833 12381 100.0 1.255 ! Near Maximum !
+00.0 107 101.00 3272 3923 64554 12451 100.0 1.214 !DANGEROUS LOAD-DO NOT USE!
+02.0 109 103.02 3335 4074 69692 12517 100.0 1.175 !DANGEROUS LOAD-DO NOT USE!
+04.0 111 105.04 3397 4227 75296 12578 100.0 1.137 !DANGEROUS LOAD-DO NOT USE!
+06.0 113 107.06 3458 4381 81357 12635 100.0 1.100 !DANGEROUS LOAD-DO NOT USE!
+08.0 115 109.08 3519 4537 87930 12686 100.0 1.065 !DANGEROUS LOAD-DO NOT USE!
+10.0 117 111.10 3580 4695 95072 12732 100.0 1.032 !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 107 101.00 3399 4232 80390 12005 100.0 1.115 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 107 101.00 3077 3468 50746 13024 99.5 1.345

 

[Powerstroke]

Thanks POP !

Figured I'd back the 180's off a grain and give it another try.