wyo7200
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Post by wyo7200 on Jun 11, 2015 18:33:01 GMT -7
Thought I'd start a thread dedicated to QuickLoad and Chris Long's Optimal Barrel Time concept. Further information about Chris Long's concept can be found at his website at the bottom of this post. Highly recommend looking into it. QuickLoad, is a very powerful reloading software that estimates how components "perform". QL allows you to change variables in its software to match YOUR components. Combined with the OBT theory... You can take a lot of the guess work out of load development. (Caveats apply- QL is a modeling software that is a supplement to published load data. KNOW YOUR RIFLE's limits and SAFETY FIRST!!!) To use these tools accurately, you need your fired case's H2O capacity, OAL, bullet brand and gr weight, powder & charge, barrel length and the chronographed velocity. Those variables are entered into the software, which produces an estimate of case fill capacity, PSI, velocity, bullet time in the barrel, % of powder burnt, etc. After seeing the results, you can tweaking the charge or the adjust the seating depth to coincide with an OBT node. This also shows why a certain combination may not be performing as expected. (i.e. .308 180gr Accubond out of a 16" barrel) I have tuned all of my rifles loads using this combination, and have achieved excellent results. Depending on ho well I do in the draw, I may be adding the Pressure Trace II equipment to my collection as well. If anyone wants to test it, feel free to contact me.
OBTQuickLoad
(QL is a modeling software that is a supplement to published load data. KNOW YOUR RIFLE's limits and SAFETY FIRST!!!)
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Post by Admin on Jun 11, 2015 20:52:15 GMT -7
Opened this site and started reading. Chris Long presents a comprehensive review of the Optimal Barrel Time concept. Might be a great way to find the optimal load
for any given rifle and could save a lot of time, money and components in the process.
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wyo7200
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Post by wyo7200 on Jun 13, 2015 16:02:04 GMT -7
Here's an example of how this process can help in load development. Please keep in mind that your results will be different than what is below because your components measurements are different than what I am using for this example.
Using a .260 Remington, 140gr Amax, 2.800 COL, 53.5gr H2O case capacity, *AS LISTED POWDER BURN RATE, 24" barrel as an example.
OBT times for a 24" barrel:
0.8160 0.8948 1.0221 1.1016 1.2282 1.3084 1.4343
I'll start with a recommended powder from Hogdgon's reloading data center H4350:
Hodgdon H4350 .264" 2.780" 39.0 2,530 51,900 PSI 42.0 2,677 58,800 PSI
They used a 24" barrel and a 140gr Nosler Partition for the test.
So, I'll enter a middle range charge of 41.6gr into QL, which gives me an ESTIMATED barrel time of 1.230, but I am close to the estimated max PSI for the caliber. It looks like I can play it safer and reach the 1.30 node by decreasing the charge to 39.9-40gr.
Cartridge : .260 Rem
Bullet : .264, 140, Hornady A-MAX 26332
Useable Case Capaci: 45.588 grain H2O = 2.960 cm³
Cartridge O.A.L. L6: 2.800 inch = 71.12 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Hodgdon H4350
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 35.91 2363 1736 37833 7984 93.7 1.492
-09.0 88 36.31 2388 1772 38977 8082 94.1 1.470
-08.0 89 36.71 2413 1809 40150 8179 94.6 1.450
-07.0 90 37.11 2437 1847 41352 8273 95.0 1.430
-06.0 91 37.51 2462 1884 42585 8365 95.4 1.411
-05.0 92 37.91 2487 1922 43850 8456 95.8 1.392
-04.0 93 38.30 2512 1961 45153 8544 96.1 1.373
-03.0 94 38.70 2536 2000 46494 8630 96.5 1.355
-02.0 95 39.10 2561 2039 47875 8714 96.8 1.337
-01.0 96 39.50 2586 2078 49298 8796 97.1 1.319
+00.0 97 39.90 2610 2118 50762 8875 97.4 1.302
+01.0 98 40.30 2635 2158 52271 8951 97.7 1.284 ! Near Maximum !
+02.0 99 40.70 2659 2198 53826 9026 98.0 1.268 ! Near Maximum !
+03.0 100 41.10 2684 2239 55427 9097 98.2 1.251 ! Near Maximum !
+04.0 101 41.50 2708 2280 57078 9166 98.5 1.235 ! Near Maximum !
+05.0 102 41.90 2733 2321 58779 9232 98.7 1.219 ! Near Maximum !
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 39.90 2673 2221 55238 8881 99.1 1.255 ! Near Maximum !
Data for burning rate decreased by 5% relative to nominal value:
-Ba 97 39.90 2538 2002 46334 8767 94.8 1.355
Using that barrel time, QL estimates how that powder performs against others by running another estimate on barrel time: * this doesnt mean that ANY powder listed can work- it is just an estimate and caution should be taken when using a powder that is not listed in any reloading manuals. I'd choose the slowest burning powder in the list if possible.
Cartridge : .260 Rem
Bullet : .264, 140, Hornady A-MAX 26332
Useable Case Capaci: 45.588 grain H2O = 2.960 cm³
Cartridge O.A.L. L6: 2.800 inch = 71.12 mm
Barrel Length : 24.0 inch = 609.6 mm
Predicted Data for Indicated Charges of the Following Powders.
Matching Barrel Time: 1.302 milliseconds
These calculations refer to your specified settings in QuickLOAD 'Cartridge Dimensions' window.
C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !
38 loads produced a Loading Ratio below user-defined minimum of 80%. These powders have been skipped.
Powder type Filling/Loading Ratio Charge Charge Vel. Prop.Burnt P max P muzz B_Time
% Grains Gramm fps % psi psi ms
--------------------------------- -----------------------------------------------------------------
Alliant Reloder-17 90.5 39.9 2.59 2692 100.0 49126 9330 1.302
Accurate 4350 96.0 40.3 2.61 2688 99.8 52374 9245 1.302 ! Near Maximum !
Accurate 3100 105.6 44.4 2.88 2673 99.0 52495 9279 1.302 ! Near Maximum !
Vihtavuori N550 92.8 39.8 2.58 2671 99.7 51399 9290 1.302 ! Near Maximum !
IMR 7828 SSC 101.0 43.6 2.83 2669 94.2 48596 10020 1.302
Ramshot Hunter 95.5 41.5 2.69 2668 98.7 50058 9490 1.302
Winchester 760 90.2 40.1 2.60 2665 98.1 50490 9453 1.302
Hodgdon H414 90.2 40.1 2.60 2665 98.1 50490 9453 1.302
Norma URP 95.4 39.6 2.57 2665 99.7 50855 9175 1.302
IMR 4831 100.8 40.5 2.63 2664 99.8 51717 9029 1.302 ! Near Maximum !
Ramshot Magnum 103.4 47.3 3.07 2662 96.7 48772 9807 1.302
Alliant Reloder-19 99.6 41.9 2.71 2654 96.3 49640 9599 1.302
Norma 203 old 89.4 38.0 2.46 2653 100.0 53287 8558 1.301 ! Near Maximum !
Accurate 4064 90.1 37.0 2.40 2646 100.0 55544 8042 1.302 ! Near Maximum !
IMR 4895 85.8 36.1 2.34 2645 100.0 51947 8707 1.302 ! Near Maximum !
Hodgdon CFE223 81.1 38.0 2.46 2641 100.0 51015 8682 1.302
Ramshot Big Game 85.9 38.4 2.49 2639 100.0 50883 8719 1.302
Hodgdon H380 88.4 38.0 2.46 2639 99.6 52348 8834 1.301 ! Near Maximum !
Hodgdon BL-C2 82.2 37.7 2.44 2639 100.0 52239 8519 1.302 ! Near Maximum !
Alliant Reloder-15 86.6 36.4 2.36 2638 100.0 51952 8685 1.302 ! Near Maximum !
Norma 203B 87.1 36.6 2.37 2637 100.0 51992 8621 1.302 ! Near Maximum !
Hodgdon H1000 111.5 46.3 3.00 2635 93.9 48720 9784 1.302
Norma 204 94.5 41.0 2.66 2634 96.1 49910 9330 1.302
Hodgdon Hybrid 100V 98.0 39.8 2.58 2633 100.0 50615 8481 1.302
Accurate 2495 85.1 35.0 2.27 2628 100.0 56281 7730 1.303 ! Near Maximum !
Vihtavuori N170 116.5 48.4 3.14 2626 88.4 51203 9562 1.302 ! Near Maximum !
Vihtavuori N165 106.0 44.1 2.86 2626 97.0 50377 9078 1.302
Accurate 2520 82.8 36.7 2.38 2625 100.0 53685 8008 1.302 ! Near Maximum !
Winchester Supreme 780 99.0 43.9 2.84 2621 96.2 50011 9176 1.302
Hodgdon H4895 83.4 35.0 2.27 2620 100.0 52023 8381 1.302 ! Near Maximum !
Hodgdon H4831 SC 100.9 42.9 2.78 2620 93.7 49612 9339 1.302
Hodgdon H4831 105.0 42.9 2.78 2620 93.7 49612 9339 1.302
Ramshot Wild Boar 82.0 36.8 2.39 2618 100.0 51548 8474 1.302 ! Near Maximum !
Vihtavuori 20N29 124.3 56.2 3.64 2615 83.8 49560 10062 1.302
Hodgdon H4350 97.1 39.9 2.59 2610 97.4 50762 8875 1.302
IMR 4350 95.2 39.8 2.58 2610 97.5 50776 8861 1.302
IMR 3031 86.1 33.8 2.19 2608 100.0 52455 7744 1.302 ! Near Maximum !
IMR 4007 SSC 89.9 38.3 2.48 2608 97.7 52006 8782 1.302 ! Near Maximum !
Norma 201 85.6 35.2 2.28 2605 100.0 53330 8061 1.303 ! Near Maximum !
IMR 4320 87.7 36.2 2.35 2602 100.0 50472 8335 1.302
Ramshot TAC 82.1 37.2 2.41 2601 99.2 51719 8559 1.301 ! Near Maximum !
Vihtavuori N160 105.4 42.5 2.75 2597 94.9 50608 8900 1.302
Vihtavuori N150 95.9 38.0 2.46 2595 100.0 52518 7961 1.302 ! Near Maximum !
Vihtavuori N540 86.8 36.9 2.39 2593 100.0 52628 7926 1.302 ! Near Maximum !
Vihtavuori N530 80.5 34.0 2.20 2593 100.0 51925 8019 1.302 ! Near Maximum !
IMR 4064 89.4 35.5 2.30 2592 99.9 51623 8191 1.302 ! Near Maximum !
Hodgdon VARGET 88.6 36.0 2.33 2591 99.9 51092 8333 1.302
Norma 202 84.5 34.9 2.26 2590 100.0 52796 7763 1.302 ! Near Maximum !
IMR 8208 XBR 82.2 34.5 2.24 2584 100.0 51839 7933 1.302 ! Near Maximum !
Ramshot X-Terminator 80.1 35.9 2.33 2581 100.0 52075 8068 1.302 ! Near Maximum !
Vihtavuori N135 92.7 35.3 2.29 2572 100.0 53740 7321 1.302 ! Near Maximum !
Accurate 2700 90.3 39.6 2.57 2572 97.6 52512 8313 1.302 ! Near Maximum !
Alliant AR-Comp 82.3 33.4 2.17 2568 100.0 53424 7195 1.302 ! Near Maximum !
Vihtavuori N140 86.5 35.6 2.31 2565 100.0 52679 7479 1.302 ! Near Maximum !
Hodgdon H322 80.1 32.7 2.12 2565 100.0 51939 7487 1.303 ! Near Maximum !
Hodgdon Benchmark 81.6 33.8 2.19 2550 100.0 52134 7552 1.302 ! Near Maximum !
Alliant Reloder-12 80.5 34.5 2.24 2549 100.0 52491 7348 1.302 ! Near Maximum !
Accurate 2015 81.7 32.8 2.13 2545 100.0 54590 7058 1.302 ! Near Maximum !
Vihtavuori N133 86.3 33.2 2.15 2509 100.0 53151 6821 1.302 ! Near Maximum !
Vihtavuori N130 81.7 32.1 2.08 2502 100.0 53904 6742 1.302 ! Near Maximum !
Reloder- 17 looks like you can get 80 more FPS with a lower PSI.
Changing powders estimates to:
Cartridge : .260 Rem
Bullet : .264, 140, Hornady A-MAX 26332
Useable Case Capaci: 45.588 grain H2O = 2.960 cm³
Cartridge O.A.L. L6: 2.800 inch = 71.12 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Alliant Reloder-17
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 81 35.91 2440 1851 36233 8725 98.9 1.496
-09.0 82 36.31 2466 1891 37351 8804 99.1 1.477
-08.0 83 36.71 2492 1930 38502 8879 99.3 1.456
-07.0 84 37.11 2517 1970 39691 8950 99.5 1.435
-06.0 85 37.51 2543 2010 40916 9017 99.7 1.415
-05.0 86 37.91 2568 2050 42182 9080 99.8 1.395
-04.0 87 38.30 2593 2090 43487 9138 99.9 1.376
-03.0 88 38.70 2618 2131 44830 9192 100.0 1.357
-02.0 89 39.10 2643 2172 46223 9242 100.0 1.338
-01.0 90 39.50 2668 2213 47658 9287 100.0 1.320
+00.0 91 39.90 2693 2254 49140 9331 100.0 1.301
+01.0 91 40.30 2717 2295 50670 9374 100.0 1.284
+02.0 92 40.70 2742 2337 52250 9416 100.0 1.266 ! Near Maximum !
+03.0 93 41.10 2766 2378 53883 9458 100.0 1.249 ! Near Maximum !
+04.0 94 41.50 2790 2420 55566 9499 100.0 1.232 ! Near Maximum !
+05.0 95 41.90 2814 2462 57311 9539 100.0 1.216 ! Near Maximum !
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 91 39.90 2751 2353 54327 9121 100.0 1.250 ! Near Maximum !
Data for burning rate decreased by 5% relative to nominal value:
-Ba 91 39.90 2620 2133 44328 9508 99.4 1.360
The important thing is to test some rounds within published data to get a baseline of what your rifle and components do. Get chronographed velocity data because the lot that QL used for its baseline, will be different than what you are loading. If the velocities are different from the QL estimates, that means that the pressure is too. If my velocity is off from what QL lists, I can adjust it for either slower or faster burning to match the chronographed data and QL will be more accurate in estimating.
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wyo7200
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Posts: 41
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Post by wyo7200 on Jul 5, 2015 21:26:29 GMT -7
200 yard group (never mind the vmax- they were amax) shots 10-15 for this load development for my creedmoor.  |
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Post by Admin on Jul 6, 2015 17:39:35 GMT -7
What rifle/barrel are you shooting?
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wyo7200
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Posts: 41
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Post by wyo7200 on Jul 7, 2015 19:53:56 GMT -7
Its a mod 10 savage predator hunter action and barrel in a MDT TAC 21 Chassis, Vortex PST 6x24.  Need to load the summer pics up to photobucket... |
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Post by Admin on Jul 8, 2015 4:05:17 GMT -7
You Really need to come play with the other kids when we have our next long range shoot.
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wyo7200
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Post by wyo7200 on Jul 8, 2015 7:46:10 GMT -7
Here's a few summer shots- The one reminds me of the windows XP desktop background.   |
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Post by Admin on Jul 8, 2015 19:48:44 GMT -7
Like the top one, no wires in the background, just Wyoming landscape.
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wyo7200
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Post by wyo7200 on Jul 17, 2015 7:54:40 GMT -7
Here's a 300yrd target- 40gr varmeggedon out of a .223 rem 700 sps going ~3750 fps.
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Post by Admin on Jul 17, 2015 10:35:11 GMT -7
Wow, that is really zipping along....nice group, were you fighting any wind?
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wyo7200
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Post by wyo7200 on Jul 18, 2015 5:31:47 GMT -7
There was a very slight breeze- going se to nw. I was surprised to see the group drift left as much as it did- I am pretty sure that i had included the typical 10mph west to east winds that are ever present at the range into my scopes original zero.
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