338 Lapua Quick load data Request

Alaska · 2026-04-01T15:42:49-0700

Requesting 338 Lapua Quick Load data needed

Retumbo Powder
Lapua Brass
Fed 215
CA Mesa LR
27” Barrel

3.750 COAL
285gr ELDM

My velocity goal is 2745 fps

DrMike · 2026-04-01T18:51:54-0700

Code:

Cartridge          : .338 Lapua Mag.
Bullet             : .338, 285, Hornady ELD-M 33381 G7
Useable Case Capaci: 93.752 grain H2O = 6.087 cm³
Cartridge O.A.L. L6: 3.750 inch = 95.25 mm
Barrel Length      : 27.0 inch = 685.8 mm
Powder             : Hodgdon Retumbo

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   97    83.88   2512    3993   42162  10328    100.0    1.644
-09.0   98    84.81   2540    4082   43645  10377    100.0    1.617
-08.0   99    85.74   2567    4170   45209  10426    100.0    1.591
-07.0  100    86.68   2594    4260   46822  10474    100.0    1.566
-06.0  101    87.61   2622    4349   48499  10521    100.0    1.541
-05.0  102    88.54   2649    4440   50237  10568    100.0    1.516
-04.0  103    89.47   2676    4530   52053  10613    100.0    1.492  ! Near Maximum !
-03.0  104    90.40   2702    4621   53939  10657    100.0    1.468  ! Near Maximum !
-02.0  105    91.34   2729    4713   55901  10701    100.0    1.445  ! Near Maximum !
-01.0  106    92.27   2756    4805   57943  10743    100.0    1.422  ! Near Maximum !
+00.0  107    93.20   2782    4898   60067  10785    100.0    1.400  ! Near Maximum !
+01.0  108    94.13   2808    4991   62282  10825    100.0    1.378  !DANGEROUS LOAD-DO NOT USE!
+02.0  109    95.06   2835    5085   64586  10864    100.0    1.356  !DANGEROUS LOAD-DO NOT USE!
+03.0  110    96.00   2861    5179   66997  10903    100.0    1.335  !DANGEROUS LOAD-DO NOT USE!
+04.0  112    96.93   2887    5275   69507  10940    100.0    1.315  !DANGEROUS LOAD-DO NOT USE!
+05.0  113    97.86   2913    5370   72127  10976    100.0    1.294  !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    107    93.20   2838    5096   67358  10550    100.0    1.341  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 5% relative to nominal value:
-Ba    107    93.20   2712    4655   53477  11071    100.0    1.468  ! Near Maximum !

Alaska · 2026-04-01T18:53:22-0700

Thanks Dr Mike your the greatest
My 89.6 of Retumbo is 2792 FPS I must have a fast barrel ! I need to come down in velocity to 2745 fps to match my custom dial on scope .
I am thinking around 88.5 .
I got some loaded up at 89.2 and 88.5 .
I think I will find my velocity between these 2 loads.

Alaska · 2026-04-01T20:35:05-0700

DrMike said:

Code:

Cartridge          : .338 Lapua Mag.
Bullet             : .338, 285, Hornady ELD-M 33381 G7
Useable Case Capaci: 93.752 grain H2O = 6.087 cm³
Cartridge O.A.L. L6: 3.750 inch = 95.25 mm
Barrel Length      : 27.0 inch = 685.8 mm
Powder             : Hodgdon Retumbo

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   97    83.88   2512    3993   42162  10328    100.0    1.644
-09.0   98    84.81   2540    4082   43645  10377    100.0    1.617
-08.0   99    85.74   2567    4170   45209  10426    100.0    1.591
-07.0  100    86.68   2594    4260   46822  10474    100.0    1.566
-06.0  101    87.61   2622    4349   48499  10521    100.0    1.541
-05.0  102    88.54   2649    4440   50237  10568    100.0    1.516
-04.0  103    89.47   2676    4530   52053  10613    100.0    1.492  ! Near Maximum !
-03.0  104    90.40   2702    4621   53939  10657    100.0    1.468  ! Near Maximum !
-02.0  105    91.34   2729    4713   55901  10701    100.0    1.445  ! Near Maximum !
-01.0  106    92.27   2756    4805   57943  10743    100.0    1.422  ! Near Maximum !
+00.0  107    93.20   2782    4898   60067  10785    100.0    1.400  ! Near Maximum !
+01.0  108    94.13   2808    4991   62282  10825    100.0    1.378  !DANGEROUS LOAD-DO NOT USE!
+02.0  109    95.06   2835    5085   64586  10864    100.0    1.356  !DANGEROUS LOAD-DO NOT USE!
+03.0  110    96.00   2861    5179   66997  10903    100.0    1.335  !DANGEROUS LOAD-DO NOT USE!
+04.0  112    96.93   2887    5275   69507  10940    100.0    1.315  !DANGEROUS LOAD-DO NOT USE!
+05.0  113    97.86   2913    5370   72127  10976    100.0    1.294  !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    107    93.20   2838    5096   67358  10550    100.0    1.341  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 5% relative to nominal value:
-Ba    107    93.20   2712    4655   53477  11071    100.0    1.468  ! Near Maximum !

Mike
Are you sure the water case capacity is correct on your QL data ? Should be around 114