Photo and Loading Information from Matt45

Two Flints · February 27, 2007, 06:09:07 AM

Hello SSS,

I received the photo and Trajectory Information from Matt45. At his request I have posted this information for your perusal.

Two Flints

Trajectory for Custom .512 Lyman 320 gr. at 1225 Feet per Second
At an Elevation Angle of: 0 degrees
Ballistic Coefficients of: 1.19 1.19 1.19 1.19 1.19
Velocity Boundaries (Feet per Second) of: 800 900 1000 1050
Wind Direction is: 0.0 o'clock and a Wind Velocity of: 0.0 Miles per hour
Wind Components are (Miles per Hour): DownRange: 0.0 Cross Range: 0.0 Vertical: 0.0
Altitude: 5925 Feet Humidity: 39 Percent Pressure: 29.6 in/Hg
Temperature: 35 F
Data Printed in English Units
Range   Velocity   Energy   Momentum   Drop   Bullet Path   Wind Drift   Time of Flight
(Yards)   (Ft/Sec)   (Ft/Lbs)   (Lb-Sec)   (inches)   (inches)   (inches)   (Seconds)
0   1225.0   1072.7   1.75   0.0   -0.5   0.0   0.000000000
25   1216.5   1058.0   1.74   -0.73   3.32   0.0   0.061437421
50   1208.2   1043.5   1.73   -2.92   5.67   0.0   0.123301301
75   1199.9   1029.3   1.72   -6.6   6.53   0.0   0.185592415
100   1191.8   1015.3   1.70   -11.79   5.89   0.0   0.248311375
125   1183.7   1001.7   1.69   -18.5   3.72   0.0   0.311458618
150   1175.8   988.3   1.68   -26.77   0.0   0.0   0.375034408
175   1168.0   975.2   1.67   -36.6   -5.29   0.0   0.439038830
200   1160.3   962.3   1.66   -48.03   -12.17   0.0   0.503471786
225   1152.6   949.8   1.65   -61.07   -20.67   0.0   0.568332990
250   1145.2   937.5   1.64   -75.74   -30.8   0.0   0.633621973
275   1137.8   925.4   1.63   -92.07   -42.58   0.0   0.699338072
300   1130.5   913.7   1.62   -110.08   -56.04   0.0   0.765480435
325   1123.4   902.2   1.61   -129.78   -71.2   0.0   0.832048022
350   1116.4   890.9   1.60   -151.21   -88.08   0.0   0.899039597
375   1109.5   879.9   1.59   -174.38   -106.71   0.0   0.966453739
400   1102.7   869.2   1.58   -199.31   -127.1   0.0   1.034288832
425   1096.0   858.7   1.57   -226.03   -149.27   0.0   1.102543016
450   1089.4   848.5   1.56   -254.56   -173.25   0.0   1.171214277
475   1083.0   838.5   1.55   -284.92   -199.07   0.0   1.240300451
500   1076.7   828.7   1.54   -317.13   -226.74   0.0   1.309799196
525   1070.5   819.2   1.53   -351.22   -256.28   0.0   1.379707995
550   1064.4   810.0   1.52   -387.2   -287.72   0.0   1.450024161
575   1058.5   800.9   1.51   -425.11   -321.08   0.0   1.520744841
600   1052.7   792.1   1.51   -464.95   -356.37   0.0   1.591867019
625   1046.9   783.5   1.50   -506.76   -393.64   0.0   1.663387526
650   1041.3   775.2   1.49   -550.55   -432.88   0.0   1.735303043
675   1035.9   767.0   1.48   -596.35   -474.14   0.0   1.807610107
700   1030.5   759.1   1.47   -644.17   -517.42   0.0   1.880305115
725   1025.2   751.4   1.47   -694.05   -562.75   0.0   1.953384335
750   1020.1   743.9   1.46   -745.99   -610.15   0.0   2.026843912
775   1015.1   736.6   1.45   -800.04   -659.65   0.0   2.100679869
800   1010.2   729.5   1.44   -856.19   -711.26   0.0   2.174888074
825   1005.4   722.6   1.44   -914.48   -765.0   0.0   2.249463989
850   1000.7   715.9   1.43   -974.93   -820.9   0.0   2.324403335
875   996.2   709.4   1.42   -1037.55   -878.98   0.0   2.399702049
900   991.7   703.0   1.42   -1102.37   -939.26   0.0   2.475356226
925   987.3   696.9   1.41   -1169.42   -1001.76   0.0   2.551362111
950   983.0   690.8   1.41   -1238.7   -1066.49   0.0   2.627716097
975   978.9   684.9   1.40   -1310.24   -1133.49   0.0   2.704414714
1000   974.7   679.2   1.39   -1384.06   -1202.77   0.0   2.781454625

matt45 · February 27, 2007, 06:08:27 PM

Hello the Camp
A few points on the readout. The obvious point is that the ballistic coefficeint is an approximation. I picked the closest bullet in a reloading manual (Hornady) and went from there. I checked the data with 3 shot groups at 50, 100, and 150, and they are close.

The good news is it doesn't matter a whole bunch for most of our purposes if the coefficeint changes +/- .5 Unless someone is going to mount a scope on a Spencer

, the difference is rather small.

The column most of us will pay attention to is #6- This is the bullet path. I used a 150 yard zero because my carbine is 6" to 8" high at 100 yds. A 150 yard zero puts the bullet path 5.98 high at 100.

The group with this load posted was 1.51- and I would call me a liar unless I could prove it. So, thanks, Two Flints, for posting this for me

matt45

Harve Curry · February 27, 2007, 11:52:41 PM

I wouldn't call any shooter with a group like that at 1/4 the distance a liar

Thanks for taking the time to post your data. I need to get busy with my Spencer and share it here.

matt45 · March 16, 2007, 02:34:49 PM

... and just in case anyone is interested
The total case capacity of the the 56-50 is 47.2grs of water. As a comparison, I'm listing case capacities of a few popular calibers
45 Colt- 41.2
44 mag- 37.4
41 Mag- 32.5
357 Mag- 26.8

I've established a max case length of 1.16"- This is somewhat arbitrary, as I didn't do a chamber cast- I used a gauge, and my reading may be off. In my experience (a limited area) these straight wall cases stretch very little.