Author Topic: Re: The magic numbers = 12ftlb  (Read 5222 times)

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Offline steve33

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Re: The magic numbers = 12ftlb
« on: January 13, 2012, 10:34:12 PM »
I have a chart that if you look up your pellet weight it will give
the MAX:   FPS for 12 Ft lb
if this any good to anyone.
sorry for long list but had to type it in as can not work out how to
up load file to listing

GNS  0.0        0.1   0.2       0.3   0.4       0.5   0.6      0.7   0.8       0.9
6   948.9  941.1   933.5  926.1   918.8  911.7   904.8  898.0   891.4  884.9
7   878.5  872.3   866.3  860.3   854.5  848.8   843.2  837.7   832.3  827.0
8   821.8  816.7   811.7  806.8   802.0  797.3   792.6  788.0   783.6  779.1
9   774.8  770.5   766.3  762.2   758.1  754.1   750.2  746.3   742.5  738.7
10   735.0  731.4   727.8  724.3   720.8  717.3   713.9  710.6   707.3  704.0
11   700.8  697.7   694.6  691.5   688.4  685.4   682.5  679.5   676.7  673.8
12   671.0  668.2   665.5  662.8   660.1  657.4   654.8  652.2   649.7  647.2
13   644.7  642.2   639.8  637.4   635.0  632.6   630.3  628.0   625.7  623.5
14   621.2  619.0   616.8  614.7   612.5  610.4   608.3  606.3   604.2  602.2
15   600.2  598.2   596.2  594.2   592.3  590.4   588.5  586.6   584.8  582.9
16   581.1  579.3   577.5  575.7   574.0  572.2   570.5  568.8   567.1  565.4
17   563.8  562.1   560.5  558.8   557.2  555.6   554.1  552.5   550.9  549.4
18   547.9  546.4   544.9  543.4   541.9  540.4   539.0  537.5   536.1  534.7
19   533.3  531.9   530.5  529.1   527.7  526.4   525.0  523.7   522.4  521.1
20   519.8  518.5   517.2  515.9   514.6  513.4   512.1  510.9   509.7  508.4
21   507.2  506.0   504.8  503.6   502.5  501.3   500.1  499.0   497.8  496.7
22   495.6  494.4   493.3  492.2   491.1  490.0   488.9  487.9   486.8  485.7
23   484.7  483.6   482.6  481.5   480.5  479.5   478.5  477.5   476.5  475.5
24   474.5  473.5   472.5  471.5   470.6  469.6   468.6  467.7   466.8  465.8
25   464.9  464.0   463.0  462.1   461.2  460.3   459.4  458.5   457.6  456.7
26   455.9  455.0   454.1  453.2   452.4  451.5   450.7  449.8   449.0  448.2
27   447.3  446.5   445.7  444.9   444.1  443.2   442.4  441.6   440.8  440.1
28   439.3  438.5   437.7  436.9   436.2  435.4   434.6  433.9   433.1  432.4
29   431.6  430.9   430.2  429.4   428.7  428.0   427.2  426.5   425.8  425.1
30   424.4  423.7   423.0  422.3   421.6  420.9   420.2  419.5   418.8  418.2
31   417.5  416.9   416.2  415.5   414.9  414.2   413.5  412.9   412.2  411.6
32   411.0  410.3   409.7  409.0   408.4  407.8   407.2  406.5   405.9  405.3
33   404.7  404.1   403.5  402.9   402.2  401.6   401.0  400.5   399.9  399.3
34   398.7  398.1   397.5  396.9   396.4  395.8   395.2  394.6   394.1  393.5
35   392.9  392.4   391.8  391.3   390.7  390.2   389.6  389.1   388.5  388.0



AAs410 .177, HW98 .177, HW97k MKI .22, HW80 .22 / .25, B/fill QB78 .25, 3 x B/fill  XS78 .22,
XS B28 .22, FN19 Hawk .22, Lightng MKI Rammer .22, Remington Vectis 032 .22,
Hatsan Striker 1000s .22 / .25

Online Gambo

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Re: The magic numbers = 12ftlb
« Reply #1 on: January 13, 2012, 10:39:18 PM »
Excellent Steve, I have now made this a sticky.

Thanks for taking the time and effort to help everyone out.

atb, Gareth

Offline sme4969

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Re: The magic numbers = 12ftlb
« Reply #2 on: January 14, 2012, 03:23:04 AM »
please remember if using a springer to use light pellets to set your gun to 11.4 ish so if change pellet you stay under the 12ftlb limit ;) and heavier pellet to set a pcp ;):) other wise if you set your gun as close to limit as poss you will and i mean you will go over the limit the law allows if you change pellet weights ;) :) ie:14.5 rws pellets in a pcp set to 11.9 will be putting out well over 12ftlb when you put a 15.8 air arms pellet and the reverse if you put 15.8 to set up a springer it will be over using lighter pellets ;):) 
airarms, s200
airarms, s410 carbine
hw 77 biker fudd glided
logun s16s
rws 27

Offline Andy

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Re: Re: The magic numbers = 12ftlb
« Reply #3 on: January 15, 2012, 01:30:14 PM »
nice one Steve

would you mind if i copied that to put over on my forum its a very handy table to have

Offline steve33

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Re: The magic numbers = 12ftlb
« Reply #4 on: January 15, 2012, 06:07:21 PM »
Please do andy
I only put up to help anyone who might have old type chronos
I have 2 chrono's  a combo 625 which i take to my club
but  in my workshop i have a old  ProChrono Digital
which only give's readout in FPS

best regards
steve
AAs410 .177, HW98 .177, HW97k MKI .22, HW80 .22 / .25, B/fill QB78 .25, 3 x B/fill  XS78 .22,
XS B28 .22, FN19 Hawk .22, Lightng MKI Rammer .22, Remington Vectis 032 .22,
Hatsan Striker 1000s .22 / .25

Offline Andy

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Re: Re: The magic numbers = 12ftlb
« Reply #5 on: January 15, 2012, 06:55:25 PM »
cheers pal you never know when something like that  will come in handy

Offline sme4969

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Re: The magic numbers = 12ftlb
« Reply #6 on: January 15, 2012, 08:48:38 PM »
I have a chart that if you look up your pellet weight it will give
the MAX:   FPS for 12 Ft lb
if this any good to anyone.
sorry for long list but had to type it in as can not work out how to
up load file to listing

GNS  0.0        0.1   0.2       0.3   0.4       0.5   0.6      0.7   0.8       0.9
6   948.9  941.1   933.5  926.1   918.8  911.7   904.8  898.0   891.4  884.9
7   878.5  872.3   866.3  860.3   854.5  848.8   843.2  837.7   832.3  827.0
8   821.8  816.7   811.7  806.8   802.0  797.3   792.6  788.0   783.6  779.1
9   774.8  770.5   766.3  762.2   758.1  754.1   750.2  746.3   742.5  738.7
10   735.0  731.4   727.8  724.3   720.8  717.3   713.9  710.6   707.3  704.0
11   700.8  697.7   694.6  691.5   688.4  685.4   682.5  679.5   676.7  673.8
12   671.0  668.2   665.5  662.8   660.1  657.4   654.8  652.2   649.7  647.2
13   644.7  642.2   639.8  637.4   635.0  632.6   630.3  628.0   625.7  623.5
14   621.2  619.0   616.8  614.7   612.5  610.4   608.3  606.3   604.2  602.2
15   600.2  598.2   596.2  594.2   592.3  590.4   588.5  586.6   584.8  582.9
16   581.1  579.3   577.5  575.7   574.0  572.2   570.5  568.8   567.1  565.4
17   563.8  562.1   560.5  558.8   557.2  555.6   554.1  552.5   550.9  549.4
18   547.9  546.4   544.9  543.4   541.9  540.4   539.0  537.5   536.1  534.7
19   533.3  531.9   530.5  529.1   527.7  526.4   525.0  523.7   522.4  521.1
20   519.8  518.5   517.2  515.9   514.6  513.4   512.1  510.9   509.7  508.4
21   507.2  506.0   504.8  503.6   502.5  501.3   500.1  499.0   497.8  496.7
22   495.6  494.4   493.3  492.2   491.1  490.0   488.9  487.9   486.8  485.7
23   484.7  483.6   482.6  481.5   480.5  479.5   478.5  477.5   476.5  475.5
24   474.5  473.5   472.5  471.5   470.6  469.6   468.6  467.7   466.8  465.8
25   464.9  464.0   463.0  462.1   461.2  460.3   459.4  458.5   457.6  456.7
26   455.9  455.0   454.1  453.2   452.4  451.5   450.7  449.8   449.0  448.2
27   447.3  446.5   445.7  444.9   444.1  443.2   442.4  441.6   440.8  440.1
28   439.3  438.5   437.7  436.9   436.2  435.4   434.6  433.9   433.1  432.4
29   431.6  430.9   430.2  429.4   428.7  428.0   427.2  426.5   425.8  425.1
30   424.4  423.7   423.0  422.3   421.6  420.9   420.2  419.5   418.8  418.2
31   417.5  416.9   416.2  415.5   414.9  414.2   413.5  412.9   412.2  411.6
32   411.0  410.3   409.7  409.0   408.4  407.8   407.2  406.5   405.9  405.3
33   404.7  404.1   403.5  402.9   402.2  401.6   401.0  400.5   399.9  399.3
34   398.7  398.1   397.5  396.9   396.4  395.8   395.2  394.6   394.1  393.5
35   392.9  392.4   391.8  391.3   390.7  390.2   389.6  389.1   388.5  388.0
this is for converting above into ftlbs ;) ie:610 x 610 x 14.5 divided by 450240 = 11.98
airarms, s200
airarms, s410 carbine
hw 77 biker fudd glided
logun s16s
rws 27

Offline anightrains

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Re: The magic numbers = 12ftlb
« Reply #7 on: January 19, 2012, 10:24:27 PM »
thanks for the post steve
brian
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Offline foxabilo

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Re: The magic numbers = 12ftlb
« Reply #8 on: January 21, 2012, 12:12:18 AM »
Just to correct some mathematical and physics and general errors in some of the replys in this section,

Look I dont want to come off as some smarty pants maths dude.... but erm.. thats what I am, so here goes


An Air gun taken as a perfect system with no friction recoil energy loss or anything will output the same KE /ft/lb no matter what grain pellet you put in it. F=MA the F being the result, A is the acceleration which would be how much gas/spring power you have.
(technically A= is a time function and has to be integrated  as a large group of changing values under one umbrella, as the gas expands for a set time and the spring expands for a set time, but for arguments sake lets say these events are instant)
OK

So in a perfect world 10ft/lb with 10grs would give a certain speed and 10fl/lb with 20 grains would be half the speed but carry the same KE.

But its not a perfect world, a C02/Pressure air gun will typically deliver the same energy output to any weight of pellet, so a fat boy 20 grain would kick ass and may be over the limit, hard to do with c02 unless you tune them.

Sringers have a different reaction as they recoil they build up gass pressure and the mass of the pellet has a direct relationship to the "echo" wave sent back to the piston as it moves, so a heavy pellet in a springer will result in a lower FPS and therefore a lower ft/lb rating , a lighter pellet will effect the spring less and give you a faster FPS giving a higher ft/lb reading.


e.g my tuned c02 78 gives 11.26ftlb with 14.66 grains thats calculated by the chrono v4. with a 19.2 grain Riono @ 530 fps, its 11.98 Ft/lb.. (wheeew) lucky huh! , PCP/C02 will go up in power as grain gets larger, Springers will go down in power. just to add to the confusion this is all @ 14 centigrade, as the temp goes down c02 power goes down and as it goes up so the power goes up. @40c a UK tunned c02 with a heavy pellet (20 grain) will almost always be over 12ft/lb

Untunned the UK C02 might actually knock a bottle over @40c

Ta for listerning

I await the onslaught

Offline sme4969

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Re: The magic numbers = 12ftlb
« Reply #9 on: January 21, 2012, 03:47:12 PM »
that's near enough what i said and was getting at ;)  :P ;D http://planetairgun.com/index.php?topic=686.msg5339#msg5339
airarms, s200
airarms, s410 carbine
hw 77 biker fudd glided
logun s16s
rws 27