Mini Sniping with the Walther Talon Magnum

[Skjold]

After 20 years or so, I have been bitten by the Airgun bug.  I am interested in the concept of mini-sniping and am looking at designing a course around the Walther Talon Magnum in .177 that is a 10% scale of a 1000 yard course for a M-24 (Remington 700 chambered in a .308). I used a ballestic calculator for Walther and for the .308 input information based on muzzle velocity, grain, and BC of each. These are the results I have:

Manufacturer:    Winchester    Description:    Super-X™ Pointed Soft Point
Caliber:    0.308 in    Weight:    165.0 gr Ballistic Coefficient:    0.399 G1       
Muzzle Velocity:    2870.0 ft/s
Calculated Table
Range    Drop    Drop    Windage    Windage    Velocity    Mach    Energy    Time    Lead    Lead
(yd)    (in)    (MOA)    (in)    (MOA)    (ft/s)    (none)    (ft•lbs)    (s)    (in)    (MOA)
0   -1.5   ***   0.0   ***   2877.8   2.539   3033.7   0.000   0.0   ***
100   -3.7   -3.5   0.8   0.7   2649.8   2.338   2572.0   0.109   19.1   18.3
200   -10.9   -5.2   3.2   1.5   2432.8   2.146   2168.1   0.227   39.9   19.1
300   -24.0   -7.6   7.6   2.4   2226.1   1.964   1815.3   0.356   62.6   19.9
400   -44.1   -10.5   14.1   3.4   2029.6   1.790   1508.9   0.497   87.4   20.9
500   -72.6   -13.9   23.0   4.4   1843.9   1.627   1245.5   0.652   114.7   21.9
600   -111.5   -17.7   34.8   5.5   1670.5   1.474   1022.2   0.823   144.8   23.1
700   -162.8   -22.2   49.7   6.8   1511.3   1.333   836.7   1.012   178.1   24.3
800   -229.4   -27.4   68.0   8.1   1369.1   1.208   686.6   1.221   214.8   25.6
900   -314.6   -33.4   90.2   9.6   1246.9   1.100   569.6   1.450   255.3   27.1
1000   -422.1   -40.3   116.0   11.1   1148.3   1.013   483.0   1.702   299.5   28.6

Trajectory Input
Pellet Input
Weight (grns):    10.5 Crossman Premier Heavy

Ballistic Coefficient: .026   

Diameter (in.): .177   

Muzzle Velocity (fps): 1065   


Zero Range: 36 Yards   

Pellet Input
Weight (grns):    

Ballistic Coefficient:    

Diameter (in.):    

Muzzle Velocity (fps):    

   Range Input (Yds)
Zero Range:    


(yds)   Turret
Val   Clicks
U/D   Path
(in.)   Drift
(in.)   Velocity
(fps)   Energy
(ft.lbs.)   Time
(sec.)   Drop
(in.)
12   5:2   42   -0.66   0.24   946.3   20.88   0.04   0.25
24   0:0   0   -0   0.98   877.9   17.97   0.08   1.07
36   0:0   0   0   2.26   814.5   15.47   0.12   2.53
48   1:4   12   -0.75   4.13   755.6   13.32   0.16   4.74
60   3:6   30   -2.37   6.63   701   11.46   0.21   7.84
72   +1,0:5   53   -4.99   9.8   650.4   9.86   0.27   11.95
84   +1,4:0   80   -8.75   13.7   603.4   8.49   0.32   17.24
96   +1,7:6   110   -13.81   18.4   559.8   7.31   0.39   23.89
108   +1,12:0   144   -20.36   23.94   519.3   6.29   0.45   32.13
120   +1,16:6   182   -28.61   30.4   481.8   5.41   0.53   42.2



I was having trouble getting the tables to line up but if you look at the first column on the .308 table which is drop in inches, and compare to the drop in inches on the last column on the .177 table, you can see it is almost a perfect 10% scale using 12 yard increments in the Talon to simulate 100 yards. I can use the same 36 yard BZO target as used by the Army and Marine Corps to zero their M-16s. The relative sight picture would be the same. I have attached the tables as well as it is hard to compare in the post. 

[LeadHead]

For a .308???   My numbers were better..I'm surprised.

[Skjold]

It depends on the round used which in this case has a BC of .399 which is average.  There are other makes that yield a higher BC closer to .50 in which the round only drops around 330 inches at 1000 yards. This was compared with a 10.5 gr pellet with a BC of only .020 which gives a drop 42 inches which is approx 10% at 120 yards.  I have another set of charts using a 10.5 with a BC of .026 which the Crossman Primier Heavies have been known to get that gives a 33 inch drop at 120 yards simulating the better .308 rounds made as well. So when using a Walther Talon Magnum .177 as a Remington .308 simulator for mini sniping, you can get a 10% scale performance using 12 yard increments for simulated 100 yards and even use a standard military 36 yard BZO target that is sized to simulate 300 yards at 36. Just place the target at 12 yards for 100 yards, 36 for 300, 60 for 500 etc. and you will get a pretty close simulated sight picture.  Windage on the other hand will be approx double the correction when using this scale.  So as far as round drop, it is close. Windage, just double up the correction.  Now also keep in mind that all this is based on theory and calcualtions.  I will not be able to say how close this will be until I get back from my deployment in Afghanistan, purchase a Walther Talon Magnum and test my hypothises.  If anyone else has a Walther Talon in .177 that would like to try my theory, I would be interested in the results.

[AirScopes]

A little help on the formatting:

Range		Drop		Drop		Windage		Windage		Velocity		Mach		Energy		Time		Lead		Lead
(yd)		(in)		(MOA)		(in)		(MOA)		(ft/s)		(none)		(ft•lbs)		(s)		(in)		(MOA)
0		-1.5		***		0.0		***		2877.8		2.539		3033.7		0.000		0.0		***
100		-3.7		-3.5		0.8		0.7		2649.8		2.338		2572.0		0.109		19.1		18.3
200		-10.9		-5.2		3.2		1.5		2432.8		2.146		2168.1		0.227		39.9		19.1
300		-24.0		-7.6		7.6		2.4		2226.1		1.964		1815.3		0.356		62.6		19.9
400		-44.1		-10.5		14.1		3.4		2029.6		1.790		1508.9		0.497		87.4		20.9
500		-72.6		-13.9		23.0		4.4		1843.9		1.627		1245.5		0.652		114.7		21.9
600		-111.5		-17.7		34.8		5.5		1670.5		1.474		1022.2		0.823		144.8		23.1
700		-162.8		-22.2		49.7		6.8		1511.3		1.333		836.7		1.012		178.1		24.3
800		-229.4		-27.4		68.0		8.1		1369.1		1.208		686.6		1.221		214.8		25.6
900		-314.6		-33.4		90.2		9.6		1246.9		1.100		569.6		1.450		255.3		27.1
1000		-422.1		-40.3		116.0		11.1		1148.3		1.013		483.0		1.702		299.5		28.6

[AirScopes]

(yds)		Turret Val		Clicks U/D		Path (in.)		Drift (in.)		Velocity (fps)		Energy (ft.lbs.)		Time (sec.)		Drop (in.)
12		5:2		42		-0.66		0.24		946.3		20.88		0.04		0.25
24		0:0		0		-0		0.98		877.9		17.97		0.08		1.07
36		0:0		0		0		2.26		814.5		15.47		0.12		2.53
48		1:4		12		-0.75		4.13		755.6		13.32		0.16		4.74
60		3:6		30		-2.37		6.63		701		11.46		0.21		7.84
72		+1,0:5		53		-4.99		9.8		650.4		9.86		0.27		11.95
84		+1,4:0		80		-8.75		13.7		603.4		8.49		0.32		17.24
96		+1,7:6		110		-13.81		18.4		559.8		7.31		0.39		23.89
108		+1,12:0		144		-20.36		23.94		519.3		6.29		0.45		32.13
120		+1,16:6		182		-28.61		30.4		481.8		5.41		0.53		42.2