Forums46
Topics537,698
Posts9,727,883
Members87,033
|
Most Online25,604 Feb 12th, 2024
|
|
|
Quickload Propellant Burnt % question
#6369771
07/15/16 03:23 AM
|
Joined: May 2014
Posts: 1,100
TackDriver
OP
Pro Tracker
|
OP
Pro Tracker
Joined: May 2014
Posts: 1,100 |
I am pretty new to QL but learning, a thought came about when I was fiddling with QL. After selecting powders, you can see on the chart where it says Propellant burnt %. My question is, is it best to select a powder when the propellant burnt % is less than 100 %? Reason I asked is because the bullet is still being pushed out the barrel and still under force until it exits the muzzle. If the propellant is 100% burnt by the time the bullet exits the muzzle, will it have an effect on accuracy since its "free flying" down the barrel without any force behind it?
|
|
|
Re: Quickload Propellant Burnt % question
[Re: TackDriver]
#6369895
07/15/16 10:48 AM
|
Joined: Nov 2007
Posts: 9,515
RiverRider
THF Trophy Hunter
|
THF Trophy Hunter
Joined: Nov 2007
Posts: 9,515 |
Most often the powder that will burn has done so by the time the bullet has moved only a few inches. Just because the powder may be 100% consumed within six inches does not mean the gases are not still under very high pressure.
"Arguing with you always makes me thirsty." -Augustus McRae
|
|
|
Re: Quickload Propellant Burnt % question
[Re: TackDriver]
#6369936
07/15/16 12:04 PM
|
Joined: Jul 2005
Posts: 2,113
Ranch Dog
Veteran Tracker
|
Veteran Tracker
Joined: Jul 2005
Posts: 2,113 |
When selecting a powder from the list, I've found my best loads from both the greatest burnt % and case fill %.
|
|
|
Re: Quickload Propellant Burnt % question
[Re: TackDriver]
#6370203
07/15/16 04:03 PM
|
Joined: Sep 2009
Posts: 18,933
ChadTRG42
THF Celebrity
|
THF Celebrity
Joined: Sep 2009
Posts: 18,933 |
Big Stan, what caliber are we talking about, first? Selecting the right powder depends a lot on matching up the caliber and bullet you plan to shoot. Some calibers I shoot have a 95-99% burn. Some subsonics have a 75-80% burn. If you burn up all the powder used, then the round becomes more efficient in using all the powder that's available. But if you go to slower burning powder and heavier bullet, you may only get a 95% burn, but your velocity goes up, but the efficiency of doing so will go down. Kind of like an old 60's Camaro with a bigger carburetor getting more fuel into the engine and less mpg.
|
|
|
Re: Quickload Propellant Burnt % question
[Re: TackDriver]
#6370232
07/15/16 04:26 PM
|
Joined: Sep 2006
Posts: 32,479
kmon11
junior
|
junior
Joined: Sep 2006
Posts: 32,479 |
In the example below over half of the powder is burned before the bullet has traveled 2 inches and pressure is already dropping off. By the time the bullet has traveled 6 over 80% of the powder is burned. 90% burn by 9 inches. To see this in quickloads use the 8th button selection at the tip to display in tabular form.
Cartridge : 6.5 Creedmoor Hornady Bullet : .264, 140, Berger Hunt VLD #26504 Useable Case Capaci: 46.664 grain H2O = 3.030 cm³ Cartridge O.A.L. L6: 2.800 inch = 71.12 mm Barrel Length : 22.0 inch = 558.8 mm Powder : Hodgdon H4350 Charge : 42.5 grains = 2.75 grams
Estimates of the progress of combustion: NR.: x(in.) Z(%) v(fps) p(psi) t (ms)
0 0.00000 1.33 0.0 3626 0.0000 1 0.00002 1.37 0.8 3724 0.0015 2 0.00007 1.40 1.5 3823 0.0054 3 0.00019 1.48 3.0 4019 0.0100 4 0.00044 1.56 4.7 4240 0.0153 5 0.00087 1.66 6.8 4509 0.0215 6 0.00154 1.78 9.2 4827 0.0285 7 0.00255 1.92 12.2 5204 0.0364 8 0.00398 2.08 15.6 5652 0.0450 9 0.00595 2.28 19.8 6182 0.0542 10 0.00857 2.52 24.6 6793 0.0641 11 0.01197 2.78 30.1 7495 0.0744 12 0.01630 3.09 36.6 8303 0.0853 13 0.02170 3.45 43.9 9219 0.0964 14 0.02834 3.86 52.4 10250 0.1079 15 0.03641 4.32 61.9 11404 0.1197 16 0.04608 4.84 72.8 12701 0.1317 17 0.05756 5.43 85.0 14132 0.1438 18 0.07106 6.10 98.7 15703 0.1560 19 0.08681 6.84 114.1 17418 0.1684 20 0.10504 7.67 131.2 19279 0.1808 21 0.12600 8.59 150.1 21270 0.1932 22 0.14995 9.61 171.1 23395 0.2056 23 0.17716 10.72 194.0 25633 0.2180 24 0.20792 11.95 219.1 27975 0.2304 25 0.24252 13.28 246.3 30392 0.2428 26 0.28127 14.72 275.8 32871 0.2552 27 0.32448 16.27 307.5 35374 0.2675 28 0.37249 17.95 341.6 37886 0.2799 29 0.42564 19.73 377.9 40371 0.2922 30 0.48428 21.63 416.5 42795 0.3045 31 0.54879 23.65 457.3 45136 0.3168 32 0.61953 25.78 500.3 47361 0.3291 33 0.69690 28.01 545.4 49445 0.3414 34 0.78130 30.36 592.4 51362 0.3538 35 0.87314 32.80 641.3 53098 0.3662 36 0.97285 35.33 692.0 54630 0.3787 37 1.08087 37.96 744.4 55952 0.3912 38 1.19764 40.67 798.2 57055 0.4038 39 1.32362 43.46 853.4 57934 0.4165 40 1.39551 44.99 883.7 58314 0.4234 41 1.53519 47.71 937.9 58671 0.4362 42 1.57124 48.38 951.5 58714 0.4394 43 1.60777 49.04 965.1 58739 0.4426 44 1.62622 49.37 971.9 58744 0.4441 45 1.63549 49.54 975.3 58746 0.4449 46 1.63781 49.58 976.1 58746 0.4451 47 1.64014 49.62 977.0 58746 0.4453 48 1.64130 49.64 977.4 58746 0.4454 49 1.64246 49.66 977.8 58746 0.4455 50 1.79547 52.26 1032.1 58612 0.4582 51 1.95714 54.79 1086.3 58231 0.4709 52 2.12824 57.24 1140.6 57625 0.4837 53 2.30961 59.63 1194.9 56816 0.4967 54 2.50217 61.96 1249.1 55826 0.5098 55 2.70692 64.21 1303.4 54674 0.5232 56 2.92496 66.39 1357.7 53380 0.5368 57 3.15748 68.51 1411.9 51959 0.5508 58 3.40583 70.55 1466.2 50431 0.5652 59 3.67149 72.53 1520.5 48809 0.5800 60 3.95608 74.44 1574.8 47109 0.5954 61 4.26146 76.28 1629.0 45344 0.6113 62 4.58965 78.05 1683.3 43529 0.6278 63 4.94294 79.75 1737.6 41675 0.6450 64 5.32391 81.39 1791.8 39793 0.6630 65 5.73544 82.95 1846.1 37895 0.6818 66 6.18079 84.45 1900.4 35991 0.7016 67 6.66367 85.88 1954.6 34089 0.7225 68 7.18827 87.24 2008.9 32198 0.7446 69 7.75936 88.53 2063.2 30327 0.7680 70 8.38242 89.75 2117.4 28483 0.7928 71 9.06370 90.90 2171.7 26671 0.8193 72 9.81041 91.98 2226.0 24900 0.8476 73 10.63087 93.00 2280.2 23173 0.8779 74 11.53474 93.95 2334.5 21496 0.9106 75 12.53326 94.82 2388.8 19873 0.9458 76 13.63956 95.63 2443.0 18308 0.9839 77 14.86909 96.37 2497.3 16804 1.0254 78 16.24006 97.04 2551.6 15365 1.0707 79 17.77409 97.65 2605.9 13992 1.1203 80 19.49699 98.18 2660.1 12687 1.1748 81 20.43870 98.42 2687.3 12061 1.2041 82 20.56049 98.45 2690.6 11984 1.2079 83 20.59108 98.46 2691.5 11965 1.2089 84 20.60640 98.46 2691.9 11955 1.2093 85 20.61407 98.46 2692.1 11950 1.2096 86 20.61790 98.46 2692.2 11948 1.2097 87 20.61982 98.46 2692.3 11947 1.2097 88 20.62078 98.46 2692.3 11946 1.2098 89 20.62126 98.46 2692.3 11946 1.2098 Muzzle
lf the saying "Liar, Liar your pants on fire" were true Mainstream news might be fun to watch
|
|
|
Re: Quickload Propellant Burnt % question
[Re: TackDriver]
#6370250
07/15/16 04:44 PM
|
Joined: Nov 2007
Posts: 9,515
RiverRider
THF Trophy Hunter
|
THF Trophy Hunter
Joined: Nov 2007
Posts: 9,515 |
About the slowest burn completion I've been able to cook up was around twelve inches in a very large cartridge with a very slow powder. In cartridges like .308 you'll usually see burn stop at around four inches or so.
"Arguing with you always makes me thirsty." -Augustus McRae
|
|
|
Re: Quickload Propellant Burnt % question
[Re: TackDriver]
#6370256
07/15/16 04:50 PM
|
Joined: Sep 2006
Posts: 32,479
kmon11
junior
|
junior
Joined: Sep 2006
Posts: 32,479 |
With the example above but change powder to Varget and 90% burned by 5.75 inches with the other 10% burned over the next 13.6 inches or so of bullet travel.
lf the saying "Liar, Liar your pants on fire" were true Mainstream news might be fun to watch
|
|
|
Re: Quickload Propellant Burnt % question
[Re: TackDriver]
#6370635
07/15/16 11:32 PM
|
Joined: May 2014
Posts: 1,100
TackDriver
OP
Pro Tracker
|
OP
Pro Tracker
Joined: May 2014
Posts: 1,100 |
It's more understandable now. I noticed that the chart below shows that the velocity is still increasing even though 100% of the propellant has been burned. Thanks guys.
Cartridge : 7 mm Rem. Mag.(SAAMI) Bullet : .284, 175, Nosler PART SP 35645 Useable Case Capaci: 73.422 grain H2O = 4.767 cm³ Cartridge O.A.L. L6: 3.314 inch = 84.18 mm Barrel Length : 25.5 inch = 647.7 mm Powder : Alliant Reloder-26 Charge : 67.0 grains = 4.34 grams
Estimates of the progress of combustion: NR.: x(in.) Z(%) v(fps) p(psi) t (ms)
0 0.00000 1.31 0.0 3626 0.0000 1 0.00002 1.35 1.0 3726 0.0011 2 0.00007 1.38 2.0 3826 0.0040 3 0.00019 1.42 3.0 3926 0.0082 4 0.00044 1.47 4.5 4075 0.0136 5 0.00087 1.54 6.3 4249 0.0201 6 0.00154 1.62 8.6 4473 0.0277 7 0.00255 1.71 11.2 4732 0.0362 8 0.00398 1.83 14.3 5040 0.0456 9 0.00595 1.95 17.8 5383 0.0557 10 0.00857 2.10 22.0 5786 0.0667 11 0.01197 2.28 26.7 6246 0.0784 12 0.01630 2.48 32.2 6776 0.0906 13 0.02170 2.70 38.3 7360 0.1034 14 0.02834 2.95 45.2 8021 0.1166 15 0.03641 3.24 53.0 8755 0.1303 16 0.04608 3.56 61.7 9572 0.1444 17 0.05756 3.92 71.4 10473 0.1587 18 0.07106 4.33 82.3 11470 0.1734 19 0.08681 4.78 94.4 12562 0.1882 20 0.10504 5.28 107.8 13746 0.2033 21 0.12600 5.85 122.6 15032 0.2184 22 0.14995 6.47 138.9 16421 0.2337 23 0.17716 7.15 156.7 17905 0.2490 24 0.20792 7.91 176.3 19489 0.2644 25 0.24252 8.75 197.6 21169 0.2798 26 0.28127 9.66 220.7 22929 0.2953 27 0.32448 10.66 245.7 24771 0.3107 28 0.37249 11.75 272.7 26682 0.3262 29 0.42564 12.93 301.7 28651 0.3416 30 0.48428 14.22 332.7 30664 0.3570 31 0.54879 15.61 365.9 32710 0.3724 32 0.61953 17.10 401.1 34770 0.3878 33 0.69690 18.71 438.4 36830 0.4031 34 0.78130 20.44 477.9 38876 0.4185 35 0.87314 22.29 519.5 40890 0.4338 36 0.97285 24.27 563.2 42857 0.4492 37 1.08087 26.36 608.9 44758 0.4645 38 1.19764 28.59 656.6 46587 0.4799 39 1.32362 30.96 706.2 48327 0.4953 40 1.45929 33.45 757.7 49967 0.5108 41 1.60513 36.08 811.0 51497 0.5262 42 1.76164 38.85 866.0 52914 0.5418 43 1.92933 41.75 922.7 54208 0.5574 44 2.10871 44.79 980.9 55373 0.5731 45 2.30031 47.97 1040.6 56409 0.5889 46 2.50469 51.28 1101.7 57315 0.6048 47 2.72239 54.73 1164.0 58092 0.6208 48 2.95398 58.31 1227.6 58743 0.6370 49 3.10428 60.59 1267.5 59082 0.6470 50 3.24129 62.54 1301.7 59243 0.6559 51 3.31094 63.49 1318.8 59286 0.6603 52 3.34606 63.97 1327.3 59298 0.6625 53 3.36370 64.20 1331.6 59301 0.6637 54 3.38139 64.44 1335.9 59303 0.6648 55 3.39025 64.55 1338.0 59304 0.6653 56 3.39469 64.61 1339.1 59304 0.6656 57 3.39691 64.64 1339.6 59304 0.6657 58 3.39913 64.67 1340.1 59304 0.6659 59 3.54300 66.51 1374.3 59256 0.6747 60 3.69046 68.30 1408.5 59116 0.6835 61 3.84176 70.04 1442.7 58890 0.6924 62 3.99716 71.74 1476.9 58582 0.7012 63 4.15692 73.38 1511.1 58197 0.7102 64 4.32129 74.98 1545.3 57738 0.7191 65 4.49056 76.52 1579.5 57210 0.7281 66 4.66504 78.02 1613.7 56617 0.7373 67 4.84501 79.46 1647.9 55962 0.7464 68 5.03081 80.86 1682.1 55250 0.7557 69 5.22278 82.21 1716.3 54483 0.7652 70 5.42129 83.51 1750.5 53665 0.7747 71 5.62670 84.76 1784.7 52801 0.7844 72 5.83944 85.96 1818.9 51892 0.7942 73 6.05994 87.11 1853.1 50943 0.8042 74 6.28865 88.21 1887.3 49956 0.8144 75 6.52608 89.26 1921.5 48934 0.8248 76 6.77275 90.27 1955.7 47881 0.8354 77 7.02923 91.22 1989.9 46799 0.8463 78 7.29612 92.13 2024.1 45691 0.8573 79 7.57409 92.98 2058.3 44560 0.8687 80 7.86384 93.79 2092.5 43409 0.8803 81 8.16613 94.55 2126.7 42239 0.8923 82 8.48177 95.25 2160.9 41055 0.9045 83 8.81166 95.91 2195.1 39857 0.9172 84 9.15677 96.52 2229.3 38649 0.9302 85 9.51814 97.08 2263.5 37432 0.9436 86 9.89690 97.59 2297.7 36210 0.9574 87 10.29430 98.06 2331.9 34984 0.9717 88 10.71169 98.47 2366.1 33756 0.9865 89 11.15056 98.83 2400.3 32529 1.0019 90 11.61251 99.15 2434.5 31304 1.0178 91 12.09934 99.41 2468.7 30084 1.0343 92 12.61300 99.63 2502.9 28870 1.0515 93 13.15565 99.79 2537.1 27665 1.0695 94 13.72968 99.91 2571.3 26470 1.0882 95 14.33771 99.98 2605.5 25286 1.1078 96 14.89994 100.00 2635.5 24261 1.1257 97 15.37086 100.00 2659.4 23455 1.1405 98 15.84177 100.00 2682.3 22696 1.1552 99 16.31269 100.00 2704.3 21980 1.1698 100 16.78360 100.00 2725.5 21304 1.1842 101 17.25451 100.00 2745.8 20665 1.1986 102 17.72543 100.00 2765.4 20060 1.2128 103 18.19634 100.00 2784.3 19486 1.2269 104 18.66725 100.00 2802.6 18941 1.2410 105 19.13817 100.00 2820.2 18423 1.2549 106 19.60908 100.00 2837.3 17931 1.2688 107 20.07999 100.00 2853.8 17461 1.2826 108 20.55091 100.00 2869.8 17014 1.2963 109 21.02182 100.00 2885.2 16587 1.3100 110 21.49273 100.00 2900.3 16179 1.3235 111 21.96365 100.00 2914.9 15788 1.3370 112 22.43456 100.00 2929.0 15415 1.3505 113 22.90547 100.00 2942.8 15057 1.3638 114 23.37639 100.00 2956.2 14714 1.3771 115 23.54567 100.00 2960.9 14594 1.3819 Muzzle
Last edited by Big Stan; 07/15/16 11:35 PM.
|
|
|
Re: Quickload Propellant Burnt % question
[Re: kmon11]
#6370785
07/16/16 02:53 AM
|
Joined: Nov 2007
Posts: 9,515
RiverRider
THF Trophy Hunter
|
THF Trophy Hunter
Joined: Nov 2007
Posts: 9,515 |
With the example above but change powder to Varget and 90% burned by 5.75 inches with the other 10% burned over the next 13.6 inches or so of bullet travel.
You are correct, Kevin. I am a bit perplexed...this goes against what some highly regarded gun writers have said and which I always took as gospel. I haven't made much use of this function in QL, and after playing around with a few cartridges and powders I have seen some stuff that really surprised me. The few times I did check out the consumption curve, I saw confirmation of the "first few inches" dictum and never messed with it thereafter. After having played with it a bit this evening with a variety of cartridges, I can see I'm going to have to play with it a lot more to get a handle on some of the surprises I discovered. The thing is, though, once a bullet has traveled down the bore 10 or 12 inches the pressure will have fallen to about half of the peak value, and the the volume of containment will have expanded several times making the additional gas provided by the burn of the last few percent of the charge almost, if not entirely inconsequential in terms of velocity. It's actually a pretty interesting thing, and I'll be looking at some of the things I've seen that really surprised me.
"Arguing with you always makes me thirsty." -Augustus McRae
|
|
|
Re: Quickload Propellant Burnt % question
[Re: TackDriver]
#6372259
07/17/16 07:32 PM
|
Joined: Nov 2007
Posts: 9,515
RiverRider
THF Trophy Hunter
|
THF Trophy Hunter
Joined: Nov 2007
Posts: 9,515 |
Consultation with one of the "highly regarded authorities" has confirmed that the axiom stating that "all the powder that will burn does so in the first few inches ahead of the chamber" originated with Homer Powley. I knew I had stuck that factoid in my brain because it had come from a credible source, I just couldn't remember who the source was.
I wish I knew an easy way verify what QuickLOAD predicts, but I think about the best that can be done would be to see if it can predict when less than 100% burn is realized by decreasing charges and by shooting with a large sheet out in front of the muzzle. I have to wonder how Powley came to his conclusions also. Since I've not read his book I wouldn't even begin to guess.
I will restate what I think is important, though (assuming QL is right): by the time 95% of the powder has burned, the confinement volume for powder burn will have expanded to the point that the effect or influence of the burn of the last 5% of the charge will be greatly diminished.
"Arguing with you always makes me thirsty." -Augustus McRae
|
|
|
Moderated by bigbob_ftw, CCBIRDDOGMAN, Chickenman, Derek, DeRico, Duck_Hunter, hetman, jeh7mmmag, JustWingem, kmon11, kry226, kwrhuntinglab, Payne, pertnear, rifleman, sig226fan (Rguns.com), Superduty, TreeBass, txcornhusker
|