node help

[Ridgerunner665]

That looks OK to me....

 

[Dwh7271]

Ba should be .379 to come out 3234 fps with 63.5
And RR was correct. At that burn rate it is around 75K pressure.

Here it is with the Ba adjusted, your case capacity and ABLR.

Cartridge : .280 Ack Imp
Bullet : .284, 150, Nosler AccuBond LR 58734 G7
Useable Case Capaci: 63.482 grain H2O = 4.122 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Alliant Reloder-26 ?

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 81 50.80 2614 2276 35559 10631 99.4 1.475
-18.0 83 52.07 2679 2391 38310 10815 99.8 1.430
-16.0 85 53.34 2744 2507 41292 10967 100.0 1.381
-14.0 87 54.61 2807 2625 44525 11090 100.0 1.334
-12.0 89 55.88 2870 2744 48017 11206 100.0 1.289
-10.0 91 57.15 2933 2864 51751 11318 100.0 1.246
-08.0 93 58.42 2994 2985 55767 11427 100.0 1.205 ! Near Maximum !
-06.0 95 59.69 3055 3108 60093 11531 100.0 1.166 ! Near Maximum !
-04.0 97 60.96 3115 3232 64756 11631 100.0 1.128 !DANGEROUS LOAD-DO NOT USE!
-02.0 99 62.23 3175 3357 69789 11727 100.0 1.092 !DANGEROUS LOAD-DO NOT USE!
+00.0 101 63.50 3234 3484 75226 11817 100.0 1.057 !DANGEROUS LOAD-DO NOT USE!
+02.0 103 64.77 3293 3613 81108 11903 100.0 1.024 !DANGEROUS LOAD-DO NOT USE!
+04.0 105 66.04 3352 3743 87481 11984 100.0 0.992 !DANGEROUS LOAD-DO NOT USE!
+06.0 107 67.31 3411 3876 94399 12059 100.0 0.961 !DANGEROUS LOAD-DO NOT USE!
+08.0 109 68.58 3470 4010 101922 12129 100.0 0.931 !DANGEROUS LOAD-DO NOT USE!
+10.0 111 69.85 3529 4147 110123 12192 100.0 0.902 !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 101 63.50 3290 3606 84078 11589 100.0 1.014 !DANGEROUS LOAD-DO NOT USE!

 

[muzz]

Ok so here is another load I had loaded the same day just a lighter load. 62.8 gr rl 26
Same seating depth and my chrono read 5 shot average of 3195fps

So 62 gr would drop it around 3150 fps if I'm thinkin right

 

[Ridgerunner665]

I'm still not convinced on the case capacity... At 75k psi he'd have brass flowing everywhere... Likely even blowing primers.

Maybe getting an air bubble as you're adding water... Its easy to do.

 

[MAinAR]

Ok so here is another load I had loaded the same day just a lighter load. 62.8 gr rl 26
Same seating depth and my chrono read 5 shot average of 3195fps

So 62 gr would drop it around 3150 fps if I'm thinkin right

Your thinking is spot on.

At 63.5 grains fps per grain = 50.93

At 62 grains fps per grain = 50.88

So see you can adjust load to goal velocity easy like this. Lot of time when testing unknown's I will make best guess minus 5% on a powder and shoot one shot for speed then adjust charge weight to goal velocity and check again.

 

[Ridgerunner665]

Try 61 grains... Fire a few rounds over the chrono, get you some more brass to measure.

 

[muzz]

Gonna do that. Got chubby ass at the loading bench as we speak

 

[Ridgerunner665]

Dwh,
What is the default Ba? Just curious...

 

[muzz]

What is the ba?

 

[Ridgerunner665]

"Ba" is what QuickLoad calls the burn rate.

 

[muzz]

So back to the node, what node or what barrel time is it I am looking to get for accuracy

 

[Ridgerunner665]

So back to the node, what node or what barrel time is it I am looking to get for accuracy

Before I can answer that we gotta figure this other stuff out.... Case capacity, max load, and velocity.... It's all connected

 

[muzz]

Ok, as soon as the weather here stops raining I'll go shoot again

 

[Dwh7271]

RR,
Ba default is 0.3397
Default case capacity is 74
Using that case capacity to get 3234 out of 63.5 gr is a Ba of .376

 

[Dwh7271]

OK,here is is at 74 gr capacity and a Ba of 376

Cartridge : .280 Ack Imp
Bullet : .284, 150, Nosler AccuBond LR 58734
Useable Case Capaci: 65.290 grain H2O = 4.239 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Alliant Reloder-26 ?

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 79 50.80 2567 2195 33389 10655 98.9 1.517
-18.0 80 52.07 2631 2306 35898 10868 99.5 1.475
-16.0 82 53.34 2695 2420 38611 11050 99.8 1.430
-14.0 84 54.61 2759 2535 41549 11201 100.0 1.382
-12.0 86 55.88 2821 2651 44724 11325 100.0 1.336
-10.0 88 57.15 2883 2768 48122 11442 100.0 1.292
-08.0 90 58.42 2944 2887 51755 11555 100.0 1.250
-06.0 92 59.69 3004 3006 55655 11665 100.0 1.210 ! Near Maximum !
-04.0 94 60.96 3064 3127 59846 11771 100.0 1.171 ! Near Maximum !
-02.0 96 62.23 3123 3249 64352 11873 100.0 1.135 !DANGEROUS LOAD-DO NOT USE!
+00.0 98 63.50 3182 3372 69202 11971 100.0 1.099 !DANGEROUS LOAD-DO NOT USE!
+02.0 100 64.77 3240 3497 74428 12064 100.0 1.065 !DANGEROUS LOAD-DO NOT USE!
+04.0 102 66.04 3298 3623 80065 12152 100.0 1.032 !DANGEROUS LOAD-DO NOT USE!
+06.0 104 67.31 3356 3751 86154 12235 100.0 1.000 !DANGEROUS LOAD-DO NOT USE!
+08.0 106 68.58 3414 3881 92743 12313 100.0 0.970 !DANGEROUS LOAD-DO NOT USE!
+10.0 108 69.85 3471 4013 99884 12386 100.0 0.940 !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 63.50 3240 3497 77365 11737 100.0 1.053 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 5% relative to nominal value:
-Ba 98 63.50 3109 3220 61114 12255 100.0 1.153 ! Near Maximum !

 

[Ridgerunner665]

RR,
Ba default is 0.3397
Default case capacity is 74
Using that case capacity to get 3234 out of 63.5 gr is a Ba of .376

Pressure right around 70,000 psi?

 

[Dwh7271]

69202

 

[Ridgerunner665]

That explains the lack of pressure signs.... According to SAAMI, 69,100 psi is acceptable as "within tolerance".….65,000 is the maximum average pressure, 69,100 is the maximum allowed for any individual round of a particular batch.

http://saami.org/specifications_and_inf ... re_CfR.pdf

 

[muzz]

I'm still lost

 

[Ridgerunner665]

Lol... We'll get you there... Just keep doing what you're doing.