Quick load request; 375 H&H

[salmonchaser]

Looking for Vihtivori 555 300 gr. Swift A Frame; 24 inch ruger #1.
My rifle has a pretty long throat lets go with 3.60 coal.
Thanks in advance.

 

[DrMike]

Cartridge          : .375 H.& H. Mag.
Bullet             : .375, 300, Swift A-Frame SS
Useable Case Capaci: 80.509 grain H2O = 5.227 cm³
Cartridge O.A.L. L6: 3.600 inch = 91.44 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Vihtavuori N555 *C*T

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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

-10.0   95    69.03   2368    3736   46778   8265     99.0    1.326
-09.0   96    69.80   2392    3812   48053   8334     99.1    1.312
-08.0   97    70.56   2416    3888   49366   8400     99.3    1.298
-07.0   98    71.33   2440    3964   50718   8463     99.5    1.284
-06.0   99    72.10   2463    4042   52112   8523     99.6    1.271
-05.0  100    72.87   2487    4119   53547   8580     99.7    1.257  ! Near Maximum !
-04.0  101    73.63   2510    4198   55027   8633     99.8    1.244  ! Near Maximum !
-03.0  102    74.40   2534    4277   56552   8683     99.9    1.231  ! Near Maximum !
-02.0  103    75.17   2557    4356   58125   8729    100.0    1.218  ! Near Maximum !
-01.0  104    75.93   2581    4436   59747   8772    100.0    1.205  ! Near Maximum !
+00.0  105    76.70   2604    4517   61421   8811    100.0    1.192  ! Near Maximum !
+01.0  106    77.47   2627    4598   63149   8847    100.0    1.179  !DANGEROUS LOAD-DO NOT USE!
+02.0  108    78.23   2651    4680   64937   8883    100.0    1.166  !DANGEROUS LOAD-DO NOT USE!
+03.0  109    79.00   2674    4762   66791   8918    100.0    1.154  !DANGEROUS LOAD-DO NOT USE!
+04.0  110    79.77   2697    4845   68715   8952    100.0    1.141  !DANGEROUS LOAD-DO NOT USE!
+05.0  111    80.54   2720    4928   70710   8985    100.0    1.129  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 5% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 5% relative to nominal value:
+Ba    105    76.70   2660    4712   67301   8582    100.0    1.157  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 5% relative to nominal value:
-Ba    105    76.70   2536    4283   55383   8986     99.3    1.231  ! Near Maximum !

 

[salmonchaser]

Cartridge          : .375 H.& H. Mag.
Bullet             : .375, 300, Swift A-Frame SS
Useable Case Capaci: 80.509 grain H2O = 5.227 cm³
Cartridge O.A.L. L6: 3.600 inch = 91.44 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Vihtavuori N555 *C*T

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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

-10.0   95    69.03   2368    3736   46778   8265     99.0    1.326
-09.0   96    69.80   2392    3812   48053   8334     99.1    1.312
-08.0   97    70.56   2416    3888   49366   8400     99.3    1.298
-07.0   98    71.33   2440    3964   50718   8463     99.5    1.284
-06.0   99    72.10   2463    4042   52112   8523     99.6    1.271
-05.0  100    72.87   2487    4119   53547   8580     99.7    1.257  ! Near Maximum !
-04.0  101    73.63   2510    4198   55027   8633     99.8    1.244  ! Near Maximum !
-03.0  102    74.40   2534    4277   56552   8683     99.9    1.231  ! Near Maximum !
-02.0  103    75.17   2557    4356   58125   8729    100.0    1.218  ! Near Maximum !
-01.0  104    75.93   2581    4436   59747   8772    100.0    1.205  ! Near Maximum !
+00.0  105    76.70   2604    4517   61421   8811    100.0    1.192  ! Near Maximum !
+01.0  106    77.47   2627    4598   63149   8847    100.0    1.179  !DANGEROUS LOAD-DO NOT USE!
+02.0  108    78.23   2651    4680   64937   8883    100.0    1.166  !DANGEROUS LOAD-DO NOT USE!
+03.0  109    79.00   2674    4762   66791   8918    100.0    1.154  !DANGEROUS LOAD-DO NOT USE!
+04.0  110    79.77   2697    4845   68715   8952    100.0    1.141  !DANGEROUS LOAD-DO NOT USE!
+05.0  111    80.54   2720    4928   70710   8985    100.0    1.129  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 5% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 5% relative to nominal value:
+Ba    105    76.70   2660    4712   67301   8582    100.0    1.157  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 5% relative to nominal value:
-Ba    105    76.70   2536    4283   55383   8986     99.3    1.231  ! Near Maximum !

Thank you Dr. Mike.

 

[JD338]

Solid speeds for the 375 and the Swift A Frame.

JD338

 

[salmonchaser]

I asked my PH if he had any issue with me using my 375#1 for Cape Buffalo. He wants me to practice reloading speed and to use swift A frames. I have a good load with RL 15 and Nosler’s but I only have 1/2 pound of powder left. The Vihtivori powders get good speed. At the moment I can’t find any 300 gr. Swift A Frames.

 

[JD338]

Don
I’ve been looking for 300 gr AFrames myself and they are nonexistent. North Fork and Trophy Bonded Bear Claws are also unavailable.
Barnes TSX isn’t a bad choice and they’re available.

JD338

 

[RL338]

It took 85grs of N555 to break 2600fps behind the Hornady 300gr BTSP in my 375 Wby. N555 seams a little bulky and a slow burner in that case.

 

[salmonchaser]

It took 85grs of N555 to break 2600fps behind the Hornady 300gr BTSP in my 375 Wby. N555 seams a little bulky and a slow burner in that case.

Good intel, thanks I saw Vihtivori showed it for the Barnes tsx but not the Swift. Have you used 540?

 

[salmonchaser]

Don
I’ve been looking for 300 gr AFrames myself and they are nonexistent. North Fork and Trophy Bonded Bear Claws are also unavailable.
Barnes TSX isn’t a bad choice and they’re available.

JD338

300 gr tsx is second choice with my PH, partitions third. I’ve 50 weeks to get it figured out I have tsx on the way and I’m shooting some Partitions and Accubonds tomorrow.

 

[RL338]

Good intel, thanks I saw Vihtivori showed it for the Barnes tsx but not the Swift. Have you used 540?

I have not tried 540. Most powders I use are around the RL-17. I know JD has had good luck with Sta-BALL 6.5 in his 375. Hodgdon list it at the top with the 300gr Swift.

 

[JD338]

Staball 6.5 would be my starting point with the 300 gr loads.

JD338

 

[salmonchaser]

Shoot I think I have some 6.5 in the back, down on the bottom of the cabinet. I’ll give it a whirl next week.