node help

[DrMike]

For sure, measure a few more cases to ensure a reasonably accurate average. OAL?

First approximation with 160 grain AB:

Cartridge : .280 Ack Imp
Bullet : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 62.510 grain H2O = 4.059 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 82 50.88 2410 2064 30381 10554 95.2 1.602
-18.0 84 52.15 2477 2180 32642 10859 96.4 1.557
-16.0 86 53.42 2543 2298 35090 11139 97.4 1.513
-14.0 88 54.70 2610 2420 37740 11391 98.3 1.466
-12.0 90 55.97 2676 2544 40614 11613 99.0 1.415
-10.0 92 57.24 2742 2671 43731 11803 99.5 1.367
-08.0 94 58.51 2808 2801 47120 11959 99.8 1.321
-06.0 97 59.78 2873 2932 50808 12080 100.0 1.276
-04.0 99 61.06 2937 3065 54825 12172 100.0 1.232
-02.0 101 62.33 3001 3200 59210 12259 100.0 1.191 ! Near Maximum !
+00.0 103 63.60 3064 3336 64003 12341 100.0 1.150 ! Near Maximum !
+02.0 105 64.87 3127 3474 69241 12417 100.0 1.112 !DANGEROUS LOAD-DO NOT USE!
+04.0 107 66.14 3190 3614 74928 12488 100.0 1.075 !DANGEROUS LOAD-DO NOT USE!
+06.0 109 67.42 3252 3757 81132 12553 100.0 1.039 !DANGEROUS LOAD-DO NOT USE!
+08.0 111 68.69 3314 3901 87915 12612 100.0 1.004 !DANGEROUS LOAD-DO NOT USE!
+10.0 113 69.96 3376 4049 95350 12664 100.0 0.971 !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 103 63.60 3192 3620 80903 11807 100.0 1.053 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 103 63.60 2865 2915 49307 12848 98.5 1.282

 

[MAinAR]

Node chart per barrel length here:

http://www.the-long-family.com/OBT%20Table.pdf

 

[Dwh7271]

Muzz,
Here's a QL based on 72.2 gr capacity.
RR, excuse me if I'm butting in.

Cartridge : .280 Ack Imp
Bullet : .284, 150, Nosler AccuBond LR 58734 G7
Useable Case Capaci: 63.479 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 80 50.33 2371 1873 27084 10107 91.7 1.629
-18.0 82 51.59 2438 1979 29019 10453 93.3 1.585
-16.0 84 52.84 2505 2090 31105 10780 94.6 1.542
-14.0 86 54.10 2572 2203 33357 11085 95.9 1.500
-12.0 88 55.36 2639 2320 35789 11366 97.0 1.459
-10.0 90 56.62 2707 2440 38420 11621 97.9 1.413
-08.0 92 57.88 2774 2563 41269 11847 98.7 1.366
-06.0 94 59.14 2841 2688 44354 12043 99.3 1.320
-04.0 96 60.39 2908 2816 47705 12206 99.7 1.277
-02.0 98 61.65 2974 2946 51344 12334 99.9 1.234
+00.0 100 62.91 3040 3077 55304 12428 100.0 1.193 ! Near Maximum !
+02.0 102 64.17 3105 3211 59621 12504 100.0 1.153 ! Near Maximum !
+04.0 104 65.43 3169 3345 64336 12575 100.0 1.115 !DANGEROUS LOAD-DO NOT USE!
+06.0 106 66.68 3233 3482 69493 12642 100.0 1.078 !DANGEROUS LOAD-DO NOT USE!
+08.0 108 67.94 3297 3621 75130 12703 100.0 1.043 !DANGEROUS LOAD-DO NOT USE!
+10.0 110 69.20 3361 3761 81266 12758 100.0 1.008 !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 100 62.91 3122 3246 62643 12111 100.0 1.136 ! Near Maximum !
Data for burning rate decreased by 5% relative to nominal value:
-Ba 100 62.91 2937 2873 48779 12642 99.1 1.258

I didn't tweak any of the stuff in QuickLoad other than case capacity. There are other tweaks you can do to fine tune muzz.

The reason I didn't say anything on the load was it seems on the internet people just naturally seem to assume if you comment in a way that can be taken negatively, they're being flamed. I should have said something as I had exactly the same thoughts pressure wise as RR mentioned. Sorry. My 280 AI load from a 24 are around 3040 with a 150. Just where it shot the best.

I stuck the nodes sheet below this. If you look at node 4 from a 24 barrel, it's 11016. Using QL above, at the edge of dangerous loads is one at 111 and change. So to get to the node at 11016 you need to move deeper into the higher pressure/dangerous load area. Not saying you can't but as Dr Mike said a few times here, you're tickling the tail of the dragon :grin: .
I hope that helps a little?

Node Node Node Node Node Node Node
Barrel
Length, in. 1 2 3 4 5 6 7
16.0 0.5527 0.6096 0.6879 0.7458 0.8232 0.8821 0.9585
16.5 0.5691 0.6274 0.7088 0.7681 0.8485 0.9087 0.9882
17.0 0.5856 0.6452 0.7297 0.7903 0.8738 0.9354 1.0180
17.5 0.6020 0.6630 0.7506 0.8125 0.8991 0.9620 1.0477
18.0 0.6185 0.6809 0.7715 0.8348 0.9245 0.9886 1.0774
18.5 0.6350 0.6987 0.7924 0.8570 0.9498 1.0153 1.1072
19.0 0.6514 0.7165 0.8133 0.8792 0.9751 1.0419 1.1369
19.5 0.6679 0.7344 0.8341 0.9015 1.0004 1.0686 1.1666
20.0 0.6843 0.7522 0.8550 0.9237 1.0257 1.0952 1.1964
20.5 0.7008 0.7700 0.8759 0.9459 1.0510 1.1219 1.2261
21.0 0.7173 0.7878 0.8968 0.9682 1.0763 1.1485 1.2559
21.5 0.7337 0.8057 0.9177 0.9904 1.1016 1.1751 1.2856
22.0 0.7502 0.8235 0.9386 1.0126 1.1270 1.2018 1.3153
22.5 0.7666 0.8413 0.9595 1.0349 1.1523 1.2284 1.3451
23.0 0.7831 0.8591 0.9803 1.0571 1.1776 1.2551 1.3748
23.5 0.7996 0.8770 1.0012 1.0793 1.2029 1.2817 1.4046
24.0 0.8160 0.8948 1.0221 1.1016 1.2282 1.3084 1.4343
24.5 0.8325 0.9126 1.0430 1.1238 1.2535 1.3350 1.4640
25.0 0.8489 0.9305 1.0639 1.1461 1.2788 1.3617 1.4938
25.5 0.8654 0.9483 1.0848 1.1683 1.3042 1.3883 1.5235
26.0 0.8819 0.9661 1.1057 1.1905 1.3295 1.4149 1.5533
26.5 0.8983 0.9839 1.1266 1.2128 1.3548 1.4416 1.5830
27.0 0.9148 1.0018 1.1474 1.2350 1.3801 1.4682 1.6127
27.5 0.9312 1.0196 1.1683 1.2572 1.4054 1.4949 1.6425
28.0 0.9477 1.0374 1.1892 1.2795 1.4307 1.5215 1.6722
28.5 0.9642 1.0552 1.2101 1.3017 1.4560 1.5482 1.7020
29.0 0.9806 1.0731 1.2310 1.3239 1.4813 1.5748 1.7317
29.5 0.9971 1.0909 1.2519 1.3462 1.5067 1.6014 1.7614
30.0 1.0136 1.1087 1.2728 1.3684 1.5320 1.6281 1.7912
30.5 1.0300 1.1266 1.2936 1.3906 1.5573 1.6547 1.8209
31.0 1.0465 1.1444 1.3145 1.4129 1.5826 1.6814 1.8507
31.5 1.0629 1.1622 1.3354 1.4351 1.6079 1.7080 1.8804
32.0 1.0794 1.1800 1.3563 1.4573 1.6332 1.7347 1.9101
32.5 1.0959 1.1979 1.3772 1.4796 1.6585 1.7613 1.9399
33.0 1.1123 1.2157 1.3981 1.5018 1.6839 1.7879 1.9696
33.5 1.1288 1.2335 1.4190 1.5240 1.7092 1.8146 1.9994
34.0 1.1452 1.2513 1.4399 1.5463 1.7345 1.8412 2.0291
34.5 1.1617 1.2692 1.4607 1.5685 1.7598 1.8679 2.0588
35.0 1.1782 1.2870 1.4816 1.5908 1.7851 1.8945 2.0886
35.5 1.1946 1.3048 1.5025 1.6130 1.8104 1.9212 2.1183
36.0 1.2111 1.3226 1.5234 1.6352 1.8357 1.9478 2.1481
O

edit: just saw the good drs post. Sorry! Difference in usable capacity is the difference between a 150 and a 160 gr bullet I would assume.

 

[muzz]

Hornady bullet comparator measurement is 2.830" and the water measurement was 71.2 not 72.2

And 150 gr ablr bullets

 

[muzz]

Well all thank you for your help. Just be straight up with me its all good. I'm glad that I have a place to go and get help.

As you guys see it where would you be with my powder and bullet combo fora load?

 

[DrMike]

In this instance you will need to give the OAL to the tip and not to the ogive. Dewey is correct on the difference. I didn't realise it was the 150 ABLR and chose the 160 AB.

 

[Ridgerunner665]

2 things I see so far....

That burn rate is way off and the case capacity measurement seems a little light... A 280 Rem is about 72 grains, ain't it?

 

[Ridgerunner665]

What kind of brass is this?

 

[MAinAR]

Late to the show on this one but your shooting it too fast. I tune to desired speed by taking the fps per grains in your barrel and tune to speed you need.

In this case I would see goal velocity at around 3,150fps with 150LRAB in 24" barrel.

3234 / 63.5 = 50.93fps/grain in "your" barrel.

3,150fps / 50.93fps = max charge at approx 61.8grs.......that is where I would test.

On a different note, every load I have tested with RL 26 in both 7RM and 280AI have shot best with 215 primers, which would mean dropping back some more on total charge also.

 

[muzz]

It's nosler brass, and thank you I will pull bullets and start over on loads.

 

[muzz]

3506 from tip to base on coal

 

[DrMike]

Cartridge : .280 Ack Imp
Bullet : .284, 150, Nosler AccuBond LR 58734 G7
Useable Case Capaci: 49.858 grain H2O = 3.237 cm³
Cartridge O.A.L. L6: 3.506 inch = 89.05 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 91 44.72 2322 1795 28894 8922 89.3 1.549
-18.0 93 45.84 2392 1906 31138 9250 91.1 1.502
-16.0 95 46.96 2463 2021 33586 9559 92.8 1.455
-14.0 97 48.07 2535 2140 36261 9848 94.3 1.410
-12.0 100 49.19 2607 2264 39185 10112 95.6 1.360
-10.0 102 50.31 2680 2392 42397 10349 96.8 1.310
-08.0 104 51.43 2753 2524 45924 10557 97.8 1.262
-06.0 106 52.55 2826 2660 49809 10733 98.6 1.215
-04.0 109 53.66 2899 2800 54101 10874 99.3 1.170
-02.0 111 54.78 2973 2943 58855 10979 99.7 1.126 ! Near Maximum !
+00.0 113 55.90 3046 3090 64139 11044 100.0 1.084 ! Near Maximum !
+02.0 115 57.02 3118 3239 70025 11071 100.0 1.043 !DANGEROUS LOAD-DO NOT USE!
+04.0 118 58.14 3191 3391 76632 11082 100.0 1.003 !DANGEROUS LOAD-DO NOT USE!
+06.0 120 59.25 3263 3547 84057 11085 100.0 0.965 !DANGEROUS LOAD-DO NOT USE!
+08.0 122 60.37 3336 3706 92449 11080 100.0 0.928 !DANGEROUS LOAD-DO NOT USE!
+10.0 124 61.49 3408 3869 101986 11065 100.0 0.892 !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 113 55.90 3202 3415 81533 10422 100.0 0.989 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 113 55.90 2806 2622 50226 11088 94.9 1.210

 

[Ridgerunner665]

Burn rate is way off... Needs to be sped up (higher Ba number)....

And I still don't trust the capacity just yet...

If anybody is willing to undertake this, tweak the Ba number until 63.5 grains gets you 3,234 fps.... Add 5% to whatever QL has for the default Ba value and see what that does.

Muzz, measure some more cases please...

 

[muzz]

I don't have anymore fired cases, only had the one.

 

[Ridgerunner665]

Measure it again...

I don't mean to aggravate you, but the measurement you got doesn't seem right to me.... Could have been a scale issue or something.

Reason being... I'm pretty sure my wife's 270 is 72 grains, but I could be wrong (going from memory).... It is posted here on the forum somewhere though.

 

[MAinAR]

Burn rate is way off... Needs to be sped up (higher Ba number)....

I have shot over 4 lbs of RL 26 so far in the 7RM & 280 AI and the default burn rate in QL has been way off on every load I have shot as well.

I ended up pretty much adjusting velocity to reasonably known speed per bullet weight of other powders I have shot with the same bullets.....

i.e. 7RM 26" barrel with 140AB adjusted to 3,200 fps which ended up at max load per Alliants data of 71.2 gr with RL26 which is where speed was with 67.5 gr of IMR4831 which I have shot for years in this gun.

Since no data available from Alliant for the 280AI and this gun has a fast natured 27" Brux barrel that shoots known load of 60gr imr4831 with 140AB to 3,250 I adjusted speed to approx the same with RL26 (63.3 grains at 3,260)..........didn't know what else to do, but don't really have any idea as to what pressure is in the 280AI. Just reasoning that same speed at more powder = less pressure???

 

[muzz]

Same measurement . I'm not sure how much water to put in it. Do I want just a small bit above the top of case or a big rounded water ball above it
I have a picture of the water in the case but don't know how to post pictures. I can text it to someone

 

[Ridgerunner665]

Add another drop from what you have been doing.

 

[muzz]

Send me a number and I'll text a picture of what I have got

 

[Ridgerunner665]

Deleted