Looking for load suggestions for the 7mm STW. I have several hundred 160 Accubonds and plenty of Retumbo on hand but load data seems to be hard to find. Anyone using this combo? Anyone know a max charge for this combo? Thanks, 163bc

Top

I never used Retumbo in my STWs

Hodgdon list it
From 75-80.2gr from a 24" velocity 2909-3056 max pressure 53,000CUP

Looking at QL it isn't near that generous velocity from 2793-2991fps with the 80.2gr giving a 100% net fill rate. Max pressure calculated is 55,560psi.

Here is QL data.

Cartridge          : 7 mm STW
Bullet             : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 86.021 grain H2O = 5.585 cm³
Cartridge O.A.L. L6: 3.560 inch = 90.42 mm
Barrel Length      : 26.0 inch = 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   84    67.20   2555    2319   31978  11579     97.7    1.707
-18.0   86    68.88   2622    2442   34316  11857     98.6    1.661
-16.0   89    70.56   2688    2568   36835  12098     99.3    1.616
-14.0   91    72.24   2754    2695   39549  12301     99.7    1.563
-12.0   93    73.92   2820    2825   42475  12463    100.0    1.511
-10.0   95    75.60   2884    2956   45631  12586    100.0    1.462
-08.0   97    77.28   2948    3087   49047  12698    100.0    1.414
-06.0   99    78.96   3011    3220   52734  12807    100.0    1.368
-04.0  101    80.64   3072    3354   56728  12911    100.0    1.324  ! Near Maximum !
-02.0  103    82.32   3134    3489   61053  13012    100.0    1.281  ! Near Maximum !
+00.0  105    84.00   3194    3625   65744  13107    100.0    1.240  ! Near Maximum !
+02.0  107    85.68   3254    3762   70836  13198    100.0    1.201  !DANGEROUS LOAD-DO NOT USE!
+04.0  110    87.36   3314    3901   76310  13284    100.0    1.163  !DANGEROUS LOAD-DO NOT USE!
+06.0  112    89.04   3373    4042   82221  13365    100.0    1.127  !DANGEROUS LOAD-DO NOT USE!
+08.0  114    90.72   3432    4185   88613  13441    100.0    1.092  !DANGEROUS LOAD-DO NOT USE!
+10.0  116    92.40   3491    4329   95537  13511    100.0    1.058  !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    105    84.00   3310    3893   81554  12651    100.0    1.141  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba    105    84.00   3015    3230   51567  13755     99.9    1.373

In the 7mm STW Retumbo is like a pistol powder. You've got to go really slow if you want to get optimal velocities with a 160 grain bullet. There are several new (and old) powders on the market which are appropriately slow for this combination, but you'll find an almost total absence of data for them. Unless you own a chronograph, are experienced at working up loads from interpolated data, and have plenty of time to do so, don't get into reloading the STW. Or the .264 Winchester. Or the 26 Nosler. Etc.

INFO!!!!!!! ONLY!!!!!!

I simple gave QL a max pressure 63,000 max fill of 110%

 Cartridge          : 7 mm STW
Bullet             : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 87.461 grain H2O = 5.679 cm³
Cartridge O.A.L. L6: 3.650 inch = 92.71 mm
Barrel Length      : 26.0 inch = 660.4 mm

Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 63000 psi, or 434 MPa
or a maximum loading ratio or filling of 110 %
These calculations refer to your specified settings in QuickLOAD 'Cartridge Dimensions' window.
C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

169 loads produced a Loading Ratio below user-defined minimum of 80%. These powders have been skipped.
Powder type          Filling/Loading Ratio  Charge    Charge   Vel. Prop.Burnt P max  P muzz  B_Time
                                      %     Grains    Gramm   fps     %       psi     psi    ms
---------------------------------  -----------------------------------------------------------------
ADI AR 2218                        104.1     89.4     5.80    3251    99.6    63000   15628   1.243  ! Near Maximum !
Vihtavuori N570                     99.8     84.9     5.50    3209    99.1    63000   15276   1.272  ! Near Maximum !
ReloadSwiss RS 80                  102.8     89.9     5.82    3196    99.7    63000   14949   1.274  ! Near Maximum !
Alliant Reloder-33                 100.2     88.8     5.75    3191    99.3    63000   15040   1.277  ! Near Maximum !
Alliant Reloder-50                 105.9     92.3     5.98    3183    99.0    63000   15334   1.304  ! Near Maximum !
Hodgdon H870                       105.9     88.1     5.71    3179    99.8    63000   14617   1.279  ! Near Maximum !
Hodgdon Retumbo                    103.5     83.9     5.43    3160   100.0    63000   13214   1.265  ! Near Maximum !
ADI AR 2225                        103.5     83.9     5.43    3160   100.0    63000   13214   1.265  ! Near Maximum !
Norma 217                          105.6     83.8     5.43    3159   100.0    63000   13577   1.290  ! Near Maximum !
Vihtavuori N560                     91.9     75.7     4.90    3147   100.0    63000   13690   1.264  ! Near Maximum !
Accurate MAGPRO                     92.1     78.9     5.11    3140    99.7    63000   13898   1.274  ! Near Maximum !
Norma MRP 2                         99.1     79.9     5.18    3138   100.0    63000   13530   1.281  ! Near Maximum !
Bofors RP30                         99.1     79.9     5.18    3138   100.0    63000   13530   1.281  ! Near Maximum !
IMR 7828                            96.1     75.3     4.88    3136   100.0    63000   13233   1.255  ! Near Maximum !
IMR 7828 SSC                        90.9     75.3     4.88    3136   100.0    63000   13233   1.255  ! Near Maximum !
PB Clermont PCL 517                 94.4     81.2     5.26    3136   100.0    63000   13306   1.269  ! Near Maximum !
SNPE Vectan SP 12                   94.2     81.1     5.26    3135   100.0    63000   13274   1.269  ! Near Maximum !
ADI AR 2213                         92.1     75.1     4.86    3127   100.0    63000   13163   1.250  ! Near Maximum !
Norma MRP                           90.0     75.7     4.90    3127   100.0    63000   13067   1.275  ! Near Maximum !
ADI AP 2214                         95.8     80.1     5.19    3124   100.0    63000   12918   1.252  ! Near Maximum !
Alliant Reloder-26                  88.5     76.7     4.97    3123   100.0    63000   12866   1.289  ! Near Maximum !
ADI AR 2217                        100.7     80.3     5.20    3122   100.0    63000   12882   1.252  ! Near Maximum !
Hodgdon H1000                      100.7     80.3     5.20    3122   100.0    63000   12882   1.252  ! Near Maximum !
ReloadSwiss RS 70                   87.5     75.1     4.87    3121   100.0    63000   12705   1.259  ! Near Maximum !
Bofors 12,7mmRA NC1214 Lot20115087 106.4     90.7     5.88    3121    93.3    63000   14981   1.308  ! Near Maximum !
Vihtavuori 24N41                   103.0     88.5     5.73    3119    95.2    63000   14199   1.258  ! Near Maximum !
Hodgdon 50BMG                      108.4     88.7     5.75    3118    91.8    63000   14558   1.266  ! Near Maximum !
Alliant Reloder-22                  92.2     75.1     4.87    3114   100.0    63000   12999   1.270  ! Near Maximum !
Bofors RP5/NP ~approximation        92.2     75.1     4.87    3114   100.0    63000   12999   1.270  ! Near Maximum !
Raufoss RA15                        92.2     75.1     4.87    3114   100.0    63000   12999   1.270  ! Near Maximum !
Alliant Reloder-25                  97.0     77.8     5.04    3113   100.0    63000   12566   1.271  ! Near Maximum !
Bofors RP15                         94.7     75.5     4.89    3113   100.0    63000   13023   1.270  ! Near Maximum !
Winchester WXR                      94.7     75.5     4.89    3113   100.0    63000   13023   1.270  ! Near Maximum !
Accurate 8700                      110.0     92.5     6.00    3108    98.8    61725   13842   1.279  ! Near Maximum !
Hodgdon US 869                     108.0     92.7     6.01    3105    95.3    63000   14203   1.274  ! Near Maximum !
Bofors RP5 NT ~approximation        95.7     78.7     5.10    3104    99.7    63000   13220   1.251  ! Near Maximum !
Vihtavuori 20N29                   110.0     95.4     6.18    3104    97.2    61961   14280   1.295  ! Near Maximum !
SNPE Vectan SP 13                  110.0     90.6     5.87    3100    98.6    62889   13792   1.284  ! Near Maximum !
Rottweil R905                       93.7     74.9     4.86    3097   100.0    63000   12924   1.266  ! Near Maximum !
ADI AR 2209                         89.5     71.8     4.65    3086   100.0    63000   12450   1.252  ! Near Maximum !
Ramshot Magnum                      92.0     80.7     5.23    3083   100.0    63000   12362   1.276  ! Near Maximum !
Alliant Reloder-19                  89.9     72.5     4.70    3082   100.0    63000   12491   1.259  ! Near Maximum !
Bofors RP14 ~approximation          90.6     73.0     4.73    3075   100.0    63000   12405   1.260  ! Near Maximum !
Hodgdon H4831 SC                    91.3     74.4     4.82    3072   100.0    63000   12562   1.256  ! Near Maximum !
Hodgdon H4831                       95.0     74.4     4.82    3072   100.0    63000   12562   1.256  ! Near Maximum !
Hodgdon H414                        81.0     69.1     4.48    3067   100.0    63000   12062   1.265  ! Near Maximum !
Winchester 760                      81.0     69.1     4.48    3067   100.0    63000   12062   1.265  ! Near Maximum !         

Excellent stuff guys. Thanks for posting. The QL info is awesome. 163bc