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Looking to get on target faster

1450 Views 12 Replies 5 Participants Last post by Bubba FAL, Jun 12, 2009

Doc Holiday13

Discussion Starter · Apr 16, 2009

I"m going to push my personal best next weekend. I'm going for some 600 yard targets 5 1/2"diameter. I don't know if my KT barrel will do it. 90 grain TNTs all handloaded. How much will I have to dope my scope? I'm zeroed at 200 which is 2" high at 100 w/ 115grain SMK's

I know doping will vary from rifle to rifle, but what would be a good point of reference? 6 MOA elevation maybe?

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paulosantos

· #3 · Apr 16, 2009

Are you going to be testing the Speer 90 Gr. TNT or the SMK? Since you are zeroed for the SMK, if you plan on shooting the TNT, you first should confirm your zero with the TNT.

What is your velocity, scope height, altitude where you live?

Check out this thread on how to use the JBM program.

http://68forums.com/viewtopic.php?f=18&t=2699

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paulosantos

· #5 · Apr 16, 2009

Code:

Trajectory 
Input Data 
Manufacturer:  Speer  Description:  TNT™ HP  
Caliber:  0.277 in  Weight:  90.0 gr  
 
Muzzle Velocity: 2700.0 ft/s Distance to Chronograph: 0.0 ft 
 
Sight Height: 2.60 in Sight Offset: 0.00 in 
Zero Height: 0.00 in Zero Offset: 0.00 in 
Windage: 0.000 MOA Elevation: 0.000 MOA 
Line Of Sight Angle: 0.0 deg Cant Angle: 0.0 deg 
 
Wind Speed: 10.0 mph Wind Angle: 90.0 deg 
Target Speed: 10.0 mph Target Angle: 90.0 deg 
 
Temperature: 59.0 °F Pressure: 29.92 in Hg 
Humidity: 0.0 % Altitude: 100.0 ft 
 
Vital Zone Radius: 5.0 in   
 
Std. Atmosphere at Altitude: No Pressure is Corrected: Yes 
Zero at Max. Point Blank Range: No Target Relative Drops: Yes 
Mark Sound Barrier Crossing: No Include Extra Rows: No 
Output Data 
Elevation: 6.676 MOA Windage: 0.000 MOA 
 
Atmospheric Density: 0.07619 lb/ft³ Speed of Sound: 1116.5 ft/s 
 
Maximum PBR: 311 yd Maximum PBR Zero: 268 yd 
Range of Maximum Height: 156 yd Energy at Maximum PBR: 627.8 ft•lbs 
 
Sectional Density: 0.168 lb/in²   
Calculated Table 
Range Drop Drop 
(yd) (in) (MOA) 
0     -2.6  *** 
50    0.3    0.5  
100   1.8    1.7  
150   1.8    1.1  
200  -0.0   -0.0  
250  -3.8   -1.4  
300  -9.9   -3.2   
350  -18.7  -5.1  
400  -30.6  -7.3 
450  -46.1  -9.8  
500  -65.8  -12.6  
550  -90.4  -15.7 
600  -120.6 -19.2 
650  -157.1 -23.1  
700  -200.7 -27.4  
750  -252.2 -32.1  
800  -312.2 -37.3 
850  -381.4 -42.9  
900  -460.5 -48.9  
950  -550.0 -55.3 
1000 -650.7 -62.1

See less See more

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paulosantos

· #7 · Apr 16, 2009

Doc Holiday13 said:
Holy crap shaving 15 grains off my regular bullet weight will get me going a lot faster. But Damn 19 MOA. I might have to buy a 10 or 20 MOA rail so I don't have to worry about bottoming out

You should switch to H4198 for the 90 Gr. bullets, which will get you close to 2900 FPS.

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paulosantos

· #9 · Apr 16, 2009

Doc Holiday13 said:
paulosantos said:

[quote="Doc Holiday13":84kskueh]Holy crap shaving 15 grains off my regular bullet weight will get me going a lot faster. But Damn 19 MOA. I might have to buy a 10 or 20 MOA rail so I don't have to worry about bottoming out

Click to expand...

You should switch to H4198 for the 90 Gr. bullets, which will get you close to 2900 FPS.

Will do, but I won't have time to drive out to the closest powder shop between then and now. Is that a faster or slower powder than 322?[/quote:84kskueh]

Faster powder.

If you use 31 Gr. of H322, your velocity should be right around 2825 FPS.
If you use 28.6 Gr. of H4198, your velocity should be right around 2900 FPS.

If you have time, try 31 Gr. of H322. It should still be very accurate. Here are the trajectories with a MV of 2825 FPS.

Code:

Trajectory 
Input Data 
Manufacturer:  Speer  Description:  TNT™ HP  
Caliber:  0.277 in  Weight:  90.0 gr  
 
Muzzle Velocity: 2825.0 ft/s Distance to Chronograph: 0.0 ft 
 
Sight Height: 2.60 in Sight Offset: 0.00 in 
Zero Height: 0.00 in Zero Offset: 0.00 in 
Windage: 0.000 MOA Elevation: 0.000 MOA 
Line Of Sight Angle: 0.0 deg Cant Angle: 0.0 deg 
 
Wind Speed: 10.0 mph Wind Angle: 90.0 deg 
Target Speed: 10.0 mph Target Angle: 90.0 deg 
 
Temperature: 59.0 °F Pressure: 29.92 in Hg 
Humidity: 0.0 % Altitude: 100.0 ft 
 
Vital Zone Radius: 5.0 in   
 
Std. Atmosphere at Altitude: No Pressure is Corrected: Yes 
Zero at Max. Point Blank Range: No Target Relative Drops: Yes 
Mark Sound Barrier Crossing: No Include Extra Rows: No 
Output Data 
Elevation: 6.188 MOA Windage: 0.000 MOA 
 
Atmospheric Density: 0.07619 lb/ft³ Speed of Sound: 1116.5 ft/s 
 
Maximum PBR: 324 yd Maximum PBR Zero: 279 yd 
Range of Maximum Height: 163 yd Energy at Maximum PBR: 673.2 ft•lbs 
 
Sectional Density: 0.168 lb/in²   
Calculated Table 
Range Drop Drop 
(yd) (in) (MOA)  
0      -2.6 *** 
100    1.5    1.4  
200   -0.0   -0.0 
300   -8.8   -2.8  
400  -27.4   -6.5  
500  -58.9   -11.3  
600  -108.0  -17.2  
700  -180.3  -24.6  
800  -281.8  -33.6  
900  -418.1  -44.4  
1000 -594.4  -56.8

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paulosantos

· #11 · Apr 17, 2009

borderpatrol said:
When shooting longer ranges it's better to have a higher B.C. bullet. I would be more comfortable shooting the 115 SMK at 2550 than the 90 grain @ 2900. Boatails rule at long range and if the wind is a factor you are in deep doo doo. If your rifle shoots the Hornady 110's accurately they have close to .370. You may be able to run them around 2600 fps which would not be bad.

When shooting a M1-A with 168 SMK's my muzzle velocity is 2500 fps. My rifle was always zeroed at 200. My come ups to 600 yards were 16.5 minutes. I think the bullet drop chart for your 90 grain underestimates your bullet drop. B.C. diminishes with loss of velocity, drop accelerates, bullets drift more and drop more.

If your going to be allowed to single load and shoot one at a time consider a 130 grain boatail. Some have B.C.'s in the mid .44/.45 area and even if they are only running 2350 fps they will not drift as much.

The Speer 90 Gr. TNT actually performed very well out to 500 yards, even the underpowered loads. I agree that a 110 Gr. V-max would be better, especially if it is windy out.

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