QL help for the 7mmRM Please

Aussie Wanderer · Dec 20, 2024

Hi Guys,

I have been working up some loads in my son’s 7mmRM using the 162eldx. We found it pretty temperamental to be honest. There was one accuracy node that we will work on. His barrel length is 26 inches, powder is H4813sc using 64.5 grains and 65 grains. 65.5 appeared to be developing pressure signs so stopped there.
Thanks in advance and Merry Christmas to my Nosler forum family.

DrMike · Dec 20, 2024

I'm somewhat unclear on what you are looking for. I can run QL with the parameters you provide, however.

First is the optimum charge.

Code:

Cartridge          : 7 mm Rem. Mag.(SAAMI)
Bullet             : .284, 162, Hornady ELD-X 2840 G7
Useable Case Capaci: 72.032 grain H2O = 4.677 cm³
Cartridge O.A.L. L6: 3.290 inch = 83.57 mm
Barrel Length      : 26.0 inch = 660.4 mm
Powder             : Hodgdon H4831 SC *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   87    58.41   2703    2629   43538  10384     95.8    1.457
-09.0   88    59.06   2733    2687   44974  10502     96.2    1.435
-08.0   89    59.71   2763    2745   46452  10617     96.6    1.414
-07.0   90    60.36   2792    2804   47973  10728     97.0    1.393
-06.0   91    61.01   2822    2864   49539  10836     97.3    1.373
-05.0   92    61.66   2851    2924   51155  10940     97.7    1.352
-04.0   93    62.30   2881    2985   52826  11040     98.0    1.333  ! Near Maximum !
-03.0   94    62.95   2910    3047   54552  11136     98.3    1.313  ! Near Maximum !
-02.0   95    63.60   2940    3108   56336  11228     98.6    1.294  ! Near Maximum !
-01.0   96    64.25   2969    3171   58181  11315     98.8    1.275  ! Near Maximum !
+00.0   97    64.90   2998    3234   60088  11398     99.0    1.257  ! Near Maximum !
+01.0   98    65.55   3028    3297   62061  11477     99.2    1.239  !DANGEROUS LOAD-DO NOT USE!
+02.0   99    66.20   3057    3361   64101  11551     99.4    1.221  !DANGEROUS LOAD-DO NOT USE!
+03.0  100    66.85   3086    3426   66214  11621     99.6    1.203  !DANGEROUS LOAD-DO NOT USE!
+04.0  101    67.50   3115    3491   68400  11685     99.7    1.186  !DANGEROUS LOAD-DO NOT USE!
+05.0  102    68.15   3144    3556   70664  11745     99.8    1.169  !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     97    64.90   3067    3384   65630  11296     99.9    1.210  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 5% relative to nominal value:
-Ba     97    64.90   2917    3061   54600  11355     97.1    1.310  ! Near Maximum !

Then, at a charge of 64.5 g.

Code:

Cartridge          : 7 mm Rem. Mag.(SAAMI)
Bullet             : .284, 162, Hornady ELD-X 2840 G7
Useable Case Capaci: 72.032 grain H2O = 4.677 cm³
Cartridge O.A.L. L6: 3.290 inch = 83.57 mm
Barrel Length      : 26.0 inch = 660.4 mm
Powder             : Hodgdon H4831 SC *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   86    58.05   2687    2597   42761  10318     95.5    1.470
-09.0   87    58.70   2716    2654   44164  10437     96.0    1.448
-08.0   88    59.34   2746    2712   45609  10553     96.4    1.426
-07.0   89    59.99   2775    2770   47096  10665     96.8    1.405
-06.0   90    60.63   2805    2829   48626  10774     97.1    1.384
-05.0   91    61.28   2834    2889   50202  10880     97.5    1.364
-04.0   92    61.92   2863    2949   51831  10981     97.8    1.344
-03.0   93    62.57   2893    3010   53513  11079     98.1    1.325  ! Near Maximum !
-02.0   94    63.21   2922    3071   55251  11173     98.4    1.305  ! Near Maximum !
-01.0   95    63.86   2951    3133   57048  11262     98.7    1.286  ! Near Maximum !
+00.0   96    64.50   2980    3195   58905  11348     98.9    1.268  ! Near Maximum !
+01.0   97    65.15   3009    3258   60825  11429     99.1    1.250  !DANGEROUS LOAD-DO NOT USE!
+02.0   98    65.79   3039    3321   62811  11505     99.3    1.232  !DANGEROUS LOAD-DO NOT USE!
+03.0   99    66.44   3068    3385   64865  11577     99.5    1.214  !DANGEROUS LOAD-DO NOT USE!
+04.0  100    67.08   3096    3449   66991  11645     99.6    1.197  !DANGEROUS LOAD-DO NOT USE!
+05.0  101    67.73   3125    3514   69190  11707     99.7    1.180  !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     96    64.50   3050    3346   64342  11260     99.9    1.221  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 5% relative to nominal value:
-Ba     96    64.50   2899    3023   53515  11291     96.8    1.322  ! Near Maximum !

Then, at a charge of 65.0 grains.

Code:

Cartridge          : 7 mm Rem. Mag.(SAAMI)
Bullet             : .284, 162, Hornady ELD-X 2840 G7
Useable Case Capaci: 72.032 grain H2O = 4.677 cm³
Cartridge O.A.L. L6: 3.290 inch = 83.57 mm
Barrel Length      : 26.0 inch = 660.4 mm
Powder             : Hodgdon H4831 SC *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   87    58.50   2708    2637   43734  10401     95.8    1.454
-09.0   88    59.15   2737    2695   45179  10519     96.3    1.432
-08.0   89    59.80   2767    2754   46665  10633     96.7    1.411
-07.0   90    60.45   2796    2813   48195  10744     97.0    1.390
-06.0   91    61.10   2826    2873   49770  10851     97.4    1.370
-05.0   92    61.75   2856    2933   51396  10955     97.7    1.349
-04.0   93    62.40   2885    2994   53077  11054     98.0    1.330  ! Near Maximum !
-03.0   94    63.05   2915    3056   54815  11150     98.3    1.310  ! Near Maximum !
-02.0   95    63.70   2944    3118   56611  11241     98.6    1.291  ! Near Maximum !
-01.0   96    64.35   2974    3180   58468  11328     98.8    1.272  ! Near Maximum !
+00.0   97    65.00   3003    3244   60388  11411     99.1    1.254  !DANGEROUS LOAD-DO NOT USE!
+01.0   98    65.65   3032    3307   62374  11489     99.3    1.236  !DANGEROUS LOAD-DO NOT USE!
+02.0   99    66.30   3061    3371   64430  11563     99.4    1.218  !DANGEROUS LOAD-DO NOT USE!
+03.0  100    66.95   3091    3436   66556  11631     99.6    1.200  !DANGEROUS LOAD-DO NOT USE!
+04.0  101    67.60   3120    3501   68758  11695     99.7    1.183  !DANGEROUS LOAD-DO NOT USE!
+05.0  102    68.25   3149    3566   71037  11754     99.8    1.166  !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     97    65.00   3072    3394   65956  11304     99.9    1.207  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 5% relative to nominal value:
-Ba     97    65.00   2922    3071   54875  11371     97.1    1.307  ! Near Maximum !

And finally at a charge of 65.5 grains.

Code:

Cartridge          : 7 mm Rem. Mag.(SAAMI)
Bullet             : .284, 162, Hornady ELD-X 2840 G7
Useable Case Capaci: 72.032 grain H2O = 4.677 cm³
Cartridge O.A.L. L6: 3.290 inch = 83.57 mm
Barrel Length      : 26.0 inch = 660.4 mm
Powder             : Hodgdon H4831 SC *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   88    58.95   2728    2677   44730  10483     96.1    1.439
-09.0   89    59.61   2758    2736   46215  10599     96.5    1.418
-08.0   90    60.26   2788    2795   47743  10712     96.9    1.396
-07.0   91    60.92   2818    2856   49316  10821     97.3    1.375
-06.0   92    61.57   2847    2916   50941  10926     97.6    1.355
-05.0   93    62.23   2877    2978   52619  11028     98.0    1.335  ! Near Maximum !
-04.0   94    62.88   2907    3040   54355  11125     98.3    1.315  ! Near Maximum !
-03.0   95    63.54   2937    3102   56149  11218     98.5    1.296  ! Near Maximum !
-02.0   96    64.19   2966    3165   58005  11307     98.8    1.277  ! Near Maximum !
-01.0   97    64.85   2996    3228   59924  11392     99.0    1.258  ! Near Maximum !
+00.0   98    65.50   3025    3292   61910  11471     99.2    1.240  !DANGEROUS LOAD-DO NOT USE!
+01.0   99    66.16   3055    3357   63965  11547     99.4    1.222  !DANGEROUS LOAD-DO NOT USE!
+02.0  100    66.81   3084    3422   66092  11617     99.6    1.204  !DANGEROUS LOAD-DO NOT USE!
+03.0  101    67.47   3114    3487   68294  11682     99.7    1.187  !DANGEROUS LOAD-DO NOT USE!
+04.0  101    68.12   3143    3553   70575  11743     99.8    1.170  !DANGEROUS LOAD-DO NOT USE!
+05.0  102    68.78   3172    3620   72938  11798     99.9    1.153  !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     98    65.50   3094    3442   67613  11346    100.0    1.194  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 5% relative to nominal value:
-Ba     98    65.50   2945    3120   56268  11449     97.4    1.292  ! Near Maximum !

I trust you can tease out the information you need from these figures.

300WSM · Dec 21, 2024

May I ask why you're using that powder? Just experimenting or prior success?
I ask because in a rifle that is very moody especially 7mm...
I always whip out IMR 4350 and IMR 4831

Those two powders can tame the pickiest of 7mm's for me and then work from there.

I was just curious why you chose H4831...

and have a most Merry Christmas as well

Aussie Wanderer · Dec 21, 2024

Dr Mike, thank you. That was exactly what I needed thank you. Merry Christmas to you and your family.

Aussie Wanderer · Dec 21, 2024

300WSM said:
May I ask why you're using that powder? Just experimenting or prior success?
I ask because in a rifle that is very moody especially 7mm...
I always whip out IMR 4350 and IMR 4831

Those two powders can tame the pickiest of 7mm's for me and then work from there.

I was just curious why you chose H4831...

and have a most Merry Christmas as well

Merry Christmas to you as well.

We are hard pressed to get imr powders here in Australia. Have also tried H1000 without a great deal of success. Thinking I may end up back at 160nbt’s and accubonds…and totally happy with that too.

SJB358 · Dec 21, 2024

How close are you able to get to the rifling AW? I know the ELDs I’ve messed with would rather be closer than further.

Aussie Wanderer · Dec 21, 2024

Limited by magazine length. I actually converted a Mauser 98 when I was 19 to 7mmRM, that was over 30 years ago. It may well be that the barrel has finally reached its end of life too, but it still shoots moa with 150nbt’s, so still a very handy rifle.

SJB358 · Dec 21, 2024

Aussie Wanderer said:
Limited by magazine length. I actually converted a Mauser 98 when I was 19 to 7mmRM, that was over 30 years ago. It may well be that the barrel has finally reached its end of life too, but it still shoots moa with 150nbt’s, so still a very handy rifle.

If the 150 BTs shoot for you and you can get them, I’d have a tough time changing myself

That’s a very good combo.