280ai 150ELD-X Quick Load

Aussie Wanderer

Beginner
May 5, 2022
85
142
HI Guys,
First time poster, long time reader.
I was hoping someone might be able to help me out with some quickload data for my rifle. It has a 26 inch barrel and I am using H4350 with the hornady 150eldx in nosler brass. It has a really nice sweet spot at 53 grains, but 55 grains is also really nice too, just not quite as good. Both are more than what is needed by this hunter, a great position to be in. Would it be possible to find out what the pressure and approximate velocities are.
 

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  • 53 Grains 2209 150eldx.jpg
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  • 55 Grains 2209 eldx.jpg
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Thanks JD, it has been a work in progress from a poorly shooting 280rem to where it is today. Just a dud original barrel that had me questioning my capacity to shoot straight and make decent reloads. I am over the moon it is all starting to come together. I think this rifle and I are going to be real good mates ;-)
 
Would you happen to know your H20 capacity on the fired cases and OAL length of your loaded round? I could crunch the numbers better with better information. Without your data, this is what I have. Top pic is your powder charge at 55 grains, 2nd pic is where I'm increasing the powder charges closer to max.


Code:
Cartridge          : .280 Ack Imp
Bullet             : .284, 150, Hornady ELD-X 2826
Useable Case Capaci: 65.128 grain H2O = 4.229 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length      : 26.0 inch = 660.4 mm
Powder             : Hodgdon H4350 *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   84    49.50   2625    2295   39674   8834     95.8    1.470
-09.0   85    50.05   2651    2341   40837   8932     96.2    1.450
-08.0   86    50.60   2678    2389   42032   9029     96.6    1.431
-07.0   87    51.15   2705    2436   43260   9123     96.9    1.411
-06.0   88    51.70   2731    2484   44522   9215     97.3    1.392
-05.0   89    52.25   2757    2532   45820   9304     97.6    1.374
-04.0   90    52.80   2784    2581   47153   9391     97.9    1.356
-03.0   91    53.35   2810    2630   48524   9474     98.1    1.338
-02.0   92    53.90   2836    2679   49933   9555     98.4    1.321
-01.0   93    54.45   2862    2729   51382   9634     98.6    1.304
+00.0   94    55.00   2889    2779   52872   9709     98.8    1.287
+01.0   95    55.55   2915    2829   54403   9781     99.0    1.270
+02.0   96    56.10   2940    2880   55978   9850     99.2    1.254  ! Near Maximum !
+03.0   96    56.65   2966    2931   57598   9916     99.4    1.238  ! Near Maximum !
+04.0   97    57.20   2992    2982   59264   9979     99.5    1.222  ! Near Maximum !
+05.0   98    57.75   3018    3033   60977  10038     99.6    1.207  ! Near Maximum !

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     94    55.00   3004    3006   61820   9479    100.0    1.202  ! Near Maximum !
Data for burning rate decreased by 10% relative to nominal value:
-Ba     94    55.00   2731    2483   44082   9499     93.9    1.396
 
Code:
Cartridge          : .280 Ack Imp
Bullet             : .284, 150, Hornady ELD-X 2826
Useable Case Capaci: 65.128 grain H2O = 4.229 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length      : 26.0 inch = 660.4 mm
Powder             : Hodgdon H4350 *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    51.30   2712    2449   43601   9149     97.0    1.406
-09.0   88    51.87   2739    2499   44920   9243     97.4    1.387
-08.0   89    52.44   2767    2549   46276   9334     97.7    1.368
-07.0   90    53.01   2794    2600   47672   9423     98.0    1.349
-06.0   91    53.58   2821    2651   49109   9509     98.2    1.331
-05.0   92    54.15   2848    2702   50587   9591     98.5    1.313
-04.0   93    54.72   2875    2754   52108   9671     98.7    1.295
-03.0   94    55.29   2902    2805   53674   9747     98.9    1.278
-02.0   95    55.86   2929    2858   55285   9820     99.1    1.261  ! Near Maximum !
-01.0   96    56.43   2956    2910   56944   9890     99.3    1.244  ! Near Maximum !
+00.0   97    57.00   2983    2963   58652   9956     99.5    1.228  ! Near Maximum !
+01.0   98    57.57   3009    3016   60411  10019     99.6    1.212  ! Near Maximum !
+02.0   99    58.14   3036    3070   62222  10079     99.7    1.196  ! Near Maximum !
+03.0  100    58.71   3062    3123   64088  10134     99.8    1.180  ! Near Maximum !
+04.0  101    59.28   3089    3177   66010  10186     99.9    1.165  !DANGEROUS LOAD-DO NOT USE!
+05.0  102    59.85   3115    3231   67990  10235     99.9    1.150  !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     97    57.00   3093    3186   68534   9642    100.0    1.149  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba     97    57.00   2828    2663   48905   9862     95.4    1.331
 
Hi Mark,
The COAL is 3.33 inches, h2o capacity is right on 72.0 grains filled to the top of the case.
Thank you
 
I would not be able to tell your approximate velocity, this is a rough estimate after inputting your OAL and H20. You would need to run it through a chronograph to get the velocity, if you don't have one try to zero it at 100 yards and shoot at 500 yards to see how much drop you may have and crunch the drop numbers on Strelok app on your phone, and get an estimated velocity. I never tried that, just a thought I would try if I were you. How is your pressure?

Code:
Cartridge          : .280 Ack Imp
Bullet             : .284, 150, Hornady ELD-X 2826
Useable Case Capaci: 63.124 grain H2O = 4.099 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length      : 26.0 inch = 660.4 mm
Powder             : Hodgdon H4350 *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   90    51.31   2748    2515   46074   9130     97.4    1.368
-09.0   91    51.88   2776    2566   47505   9220     97.7    1.349
-08.0   92    52.45   2803    2618   48980   9307     98.0    1.330
-07.0   93    53.02   2831    2670   50499   9391     98.3    1.312
-06.0   94    53.59   2859    2722   52064   9472     98.5    1.294
-05.0   95    54.16   2887    2775   53677   9550     98.8    1.276
-04.0   96    54.73   2914    2828   55339   9625     99.0    1.259  ! Near Maximum !
-03.0   97    55.30   2942    2882   57051   9696     99.2    1.241  ! Near Maximum !
-02.0   98    55.87   2969    2936   58817   9764     99.3    1.225  ! Near Maximum !
-01.0   99    56.44   2996    2990   60637   9828     99.5    1.208  ! Near Maximum !
+00.0  100    57.01   3023    3044   62514   9888     99.6    1.192  ! Near Maximum !
+01.0  101    57.58   3050    3099   64449   9945     99.7    1.176  !DANGEROUS LOAD-DO NOT USE!
+02.0  102    58.15   3077    3154   66445   9998     99.8    1.160  !DANGEROUS LOAD-DO NOT USE!
+03.0  103    58.72   3104    3210   68505  10047     99.9    1.145  !DANGEROUS LOAD-DO NOT USE!
+04.0  104    59.29   3131    3265   70630  10092    100.0    1.130  !DANGEROUS LOAD-DO NOT USE!
+05.0  105    59.86   3158    3321   72823  10134    100.0    1.115  !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    100    57.01   3131    3265   73123   9550    100.0    1.116  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba    100    57.01   2869    2742   52048   9845     95.8    1.291
 
Welcome aboard. Mark has demonstrated that you have some room to up your charge if you're so inclined to seek a higher velocity. However, with the accuracy you're now seeing, that isn't necessarily required.

Just a note on measuring case capacity. Use deoxygenated water. Let the water sit in an uncovered container overnight. To measure case capacity, fill the case with the deoxygenated water until you have a convex meniscus. Usually, this will require you to use a pipette to add the water as you measure the weight.
 
By the way, I added the graph, I was looking at the Optimal Barrel Timing chart for a 26 inch barrel, the node is 1.1905 and the node on the graph with 57 grains of powder shows the node at 1.192 which is very close. I believe increasing your powder capacity may get to that spot, but work up slow and watch for pressure.
280ai.JPG
 
Mark that is great, thank you. I originally worked up a load using 58 grains of H4813sc which was also very accurate, but was also very compressed. Part of the attraction of the current work up is that there appears to be a fair amount of room in the case.

57 grains will give circa 100fps by the looks of it which is nice, but everything gets stressed a little harder. I think the 55 grains is probably where I will stop given what it will do...I say that now wondering what it looks like with a bit more juice :unsure::LOL::LOL:
 
You have an accurate load already.
What uses do you have in mind for this rifle?
Largest game?
Max distance you feel comfortable hunting at?
 
You have an accurate load already.
What uses do you have in mind for this rifle?
Largest game?
Max distance you feel comfortable hunting at?
Biggest deer locally is the red. I wanted this rifle to be the first one I grab for everything from wild dogs up. 400 yards would be a long shot for the majority of places I hunt.
 
Biggest deer locally is the red. I wanted this rifle to be the first one I grab for everything from wild dogs up. 400 yards would be a long shot for the majority of places I hunt.
That cartridge and bullet should do you just fine out to 400 yards.
I used a 143 ELD-X on cow/calf elk tag this past fall...Did just fine
I have shot both mule deer buck, cow and bull elk with the 7mm 175 grain ELD-X...All worked good too.
 
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